Chapter XVI: TECHNOLOGY.--Action of Caustic Soda on Wood.--By M.H (3)

The third case I saw about fourteen hours after he was struck. The patient was a healthy blacksmith, about 30 years of age. The wound was at about the middle of the forearm, the fangs entering toward the ulnar side. When I saw the patient he exhibited comparatively trifling symptoms. His heart action was rapid, and he was suffering from the typical despondency and terror, but I could not note the profound systemic depression characteristic of the great majority of cases. Surrounding the wound and extending up the forearm for several inches there was a boggy swelling, exhibiting a sharp line of demarkation. It was bronzed in color, and was apparently spreading. I at once applied the intermittent ligature just above the elbow, and injected the permanganate of potassium solution freely all through the involved tissues, particularly in the region of the bite and about the periphery of the swelling, surrounding the latter by a complete ring of injections.

The general treatment of this patient was continued on the same general line as described in the former cases, stimulants being employed moderately. He recovered without any bad symptoms. There was no sloughing; the swelling disappeared without any necrosis of tissue. He is still pursuing his trade in Cheyenne, and suffers from absolutely no disability.

I saw but one case shortly after the wound was inflicted. This patient was a healthy young man, who was struck about the middle of the dorsal surface of the hand, the fangs entering on each side of a metacarpal bone, and the poison lodging apparently in the palm of the hand. The patient, when seen, exhibited the characteristic terror and depression, weak, rapid heart action, and agonizing local pain. I made two small incisions in the region of the wound upon the dorsum of the hand, and injected permanganate of potassium freely. This patient ultimately recovered, but only after sloughing and prolonged suppuration. I believe that had I incised freely and at once from the palmar surface, I would have been spared this unpleasant complication.

I have had in all nine cases, and without a single death. The others are in their general features and in the treatment employed quite similar to those given.

The symptoms resulting from snake bite poison are strikingly like those dependent upon the violent septic poison seen in pre-antiseptic times. There is often the same prodromal chill, the high elevation of temperature, the profound effect on the circulation, and the rapid cellular involvement. The tissue disturbance following snake poisoning differs from ordinary cellulitis, however, in the following particulars: The color is _bronze_, not red; the involved area is _boggy_, not brawny; and the extension of the process is _exceedingly rapid_.

The treatment applicable to one condition seems to be equally successful when applied to the other. In cellulitis, free incisions, antiseptic lotions, and active stimulation are the three means upon which the surgeon mainly depends, and in combating the local and general symptoms excited by snake bite poisoning, the same treatment has given me the successful results detailed above. Whether or not permanganate of potassium is more active than other antiseptics in snake bite poisoning I am not prepared to state, but the high authority of S. Weir Mitchell, together with my own experience, does not incline me to substitute any other drug at present.

I would formulate the treatment for poison of the rattlesnake as follows:

1. Free incisions to the bottom of the wound and immediate cauterization; or, if this is not practicable, sucking of the wound.

2. The immediate application of an intermittent tourniquet, that is, one which is relaxed for a moment at a time, so that the poison may gain admission into the circulation in small doses.

3. The free administration of alcohol or carbonate of ammonium.

This might be termed the _urgency treatment_ of snake bite poisoning. The _curative treatment_ requires--

4. Free incisions into all portions of the inflamed tissues, and the thorough kneading into these incisions of a fifteen per cent. solution of permanganate of potassium.

5. Multiple injections of the same solution into all the inflamed regions, but particularly into the region of the wound.

6. The complete surrounding of all the involved tissues, by permanganate of potassium injections placed from half an inch to an inch apart, the needle being driven into the healthy tissue just beyond the line of demarkation, and its point being carried to the deepest part of the border of the indurated area.

7. The permanganate of potassium solution should be used freely in fifteen per cent. solution. I have used one and a half drachms of the pure drug diluted, and would not hesitate to use four times that quantity were it necessary, since it seems to exert no deleterious effect, either locally or generally.

8. The involved area should be dressed by means of lint saturated with fifteen per cent. permanganate of potassium solution. Stimulants should be given according to the indications--i.e., the condition of the pulse. Laxatives, diuretics, and diaphoretics should be administered to aid in the elimination of the poison. The diet should be as nutritious as the stomach can digest.--_The Therapeutic Gazette_.

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CHINESE COMPETITIVE EXAMINATIONS.

Wuchang, on the Yangtsze opposite Hankow, is the capital of the two provinces Hupeh and Hunan. Here, every third year, the examination for competitors from both provinces is held, and a correspondent of the _North China Herald_, of Shanghai, describes the scene at the examination at the beginning of September last. The streets, he says, are thronged with long-robed, large-spectacled gentlemen, who inform the world at large by every fold of drapery, every swagger of gait, every curve of nail, that they are the aristocracy of the most ancient empire of the world. Wuchang had from 12,000 to 15,000 bachelors of arts within its walls, who came from the far borders of the province for the examination for the provincial degree. About one-half per cent. will be successful; thousands of them know they have not the shadow of a chance, but literary etiquette binds them to appear. In the wake of these Confucian scholars come a rout of traders, painters, scroll sellers, teapot venders, candle merchants, spectacle mongers, etc.; servants and friends swell the number, so that the examination makes a difference of some 40,000 or 50,000 to the resident population. In the great examination hall, which is composed of a series of pens shut off from each other in little rows of 20 or 30, and the view of which is suggestive of a huge cattle market, there is accommodation for over 10,000 candidates. The observance of rules of academic propriety is very strict. A candidate may be excluded, not only for incompetence, but for writing his name in the wrong place, for tearing or blotting his examination paper, etc. After the examination of each batch a list of those allowed to compete for honors is published, and the essay forms for each district are prepared with proper names and particulars. The ancestors of the candidate for three generations must be recorded, they must be free from taint of _yamen_ service, prostitution, the barber's trade and the theater, or the candidate would not have obtained his first degree. With the forms 300 cash (about 1s.) are presented to each candidate for food during the ordeal. The lists being thus prepared, on the sixth day of the eighth moon (Tuesday, the 8th of September, in 1891), the city takes a holiday to witness the ceremony of "entering the curtain," i.e., opening the examination hall. For days coolies have been pumping water into great tanks, droves of pigs have been driven into the inclosure, doctors, tailors, cooks, coffins, printers, etc., have been massed within the hall for possible needs. The imperial commissioners are escorted by the examination officials to the place. A dozen district magistrates have been appointed to superintend within the walls, and as many more outside, two prefects have office inside, and the governor of the province has also to be locked up during the eight days of examination. The whole company is first entertained to breakfast at the _yamen_, and then the procession forms; the ordinary umbrellas, lictors, gongs, feathers, and ragamuffins are there in force; the examiners and the highest officers are carried in open chairs draped in scarlet and covered with tiger skins. The dead silence that falls on the crowd betokens the approach of the governor, who brings up the rear. Then the bustle of the actual examination begins. The hall is a miniature city. Practically martial law is proclaimed. In the central tower is a sword, and misdemeanor within the limits is punished with instant death. The mandarins take up their quarters in their respective lodges, the whole army of writers whose duty it is to copy out the essays of the candidates, to prevent collusion, take their places. Altogether there must be over 20,000 people shut in. Cases have been known in which a hopeful candidate was crushed to death in the crowd at the gate. Each candidate is first identified, and he is assigned a certain number which corresponds to a cell a few feet square, containing one board for a seat and one for a desk. Meanwhile the printers in the building are hard at work printing the essay texts. Each row of cells has two attendants for cooking, etc., assigned to it, the candidates take their seats, the rows are locked from the outside, the themes are handed out, the contest has begun. The examination is divided into three bouts of about 36 hours, two nights and a day, each, with intervals of a day. The first is the production of three essays on the four assigned books; the second of five essays on the five classics; the third of five essays on miscellaneous subjects. The strain, as may be imagined, is very great, and several victims die in the hall. The literary ambition which leads old men of 60 and 70 to enter not unfrequently destroys them. Should any fatal case occur, the coffin may on no account be carried out through the gates; it must be lifted over or sometimes through a breach in the wall. Death must not pollute the great entrance. At the end of the third trial, the first batch of those who have completed their essays is honored with the firing of guns, the bows of the officials, and the ministry of a band of music. Three weeks of anxious waiting will ensue before a huge crowd will assemble to see the list published. Then the successful candidates are the pride of their country side, and well do the survivors of such an ordeal deserve their credit. The case of those who are in the last selection and are left degreeless, for the stern reason that some must be crowded out, is the hardest of all.

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HIGH SPEED ENGINE AND DYNAMO.

We illustrate a high speed engine and dynamo constructed by Easton & Anderson, London. This plant was used at the Royal Agricultural Society's show at Doncaster in testing the machinery in the dairy, and constituted a distinct innovation, as well as an improvement, on the appliances previously employed for the purpose. The separator, or whatever might be the machine under trial, was driven by an electric motor fed by a current from the dynamo we illustrate. A record was made of the volts and amperes used, and from this the power expended was deduced, the motor having been previously carefully calibrated by means of a brake. So delicate was the test that the observers could detect the presence of a warm bearing in the separator from the change in the readings of the ammeter.

The engine is carefully balanced to enable it to run at the very high speed of 500 revolutions per minute. The cranks are opposite each other, and the moving parts connected with the two pistons are of the same weight. The result is complete absence of vibration, and exceedingly quiet running. Very liberal lubricating arrangements are fitted to provide for long runs, while uniformity of speed is provided for by a Pickering governor. The high pressure cylinder is 4 in. in diameter, and the low pressure cylinder is 7 in. in diameter. The stroke in each case is 4 in.

The dynamo is designed to feed sixty lamps of 16 candle power each, the current being 60 amperes at 50 volts. The armature is of the drum type. The peculiar feature of it is that grooves are planed in the laminated core from end to end, and in these grooves the conductors, which are of ribbon section, are laid. Slips of insulating material are laid between the coils and the dovetailed mouths of the grooves are closed with bone or vulcanized fiber, or other dielectric. At each end of the core there are fitted non-magnetic covers. At the commutator end the cover is like a truncated cone, and incloses the connections completely. One end of the cone is supported on the end plate of the armature and the other end on a ring on the commutator. A bell-shaped cover incloses the conductors at the other end of the armature. The result is that the conductors are completely incased, protected from all mechanical injury, and positively driven. They can neither be displaced nor abraded. The conductors on the magnet coils are likewise carefully protected from harm by metal coverings. These dynamos are made in sixteen sizes, of which seven sizes are designed to feed more than 100 lamps, the largest serving for 600 lamps.

Messrs. Easton & Anderson are showing machinery of this type at the Crystal Palace Electrical Exhibition now open in London.--_Engineering_.

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CHLORINE GAS AND SODA BY THE ELECTROLYTIC PROCESS.

The decomposition of a solution of common salt, and its conversion into chlorine gas and caustic soda solution by means of an electric current, has long been a study with electro-chemists. Experimentally it has often been effected, but so far as we are aware, the success of this method of production has never until now been demonstrated on a sound commercial basis. The solution of this important industrial problem is due to Mr. James Greenwood, who has been engaged in the development of electro-chemical processes for many years. The outcome of this is that Mr. Greenwood has now perfected an electrolytic process for the direct production of caustic soda and chlorine, as well as other chemical products, the operation of which we recently inspected at Phoenix Wharf, Battersea, London. One of the special features in connection with Mr. Greenwood's new departure is the novel and ingenious method by which the electrolyzed products are separated, and their recombination rendered impossible. This object is attained by the use of a specially constructed diaphragm which is composed of a series of V-shaped glass troughs, fitted in a frame within each other with a small space between them, which is lightly packed with asbestos fiber. Another important feature of the apparatus is a compound anode which consists of carbon plates, with a metal core to increase the conductivity. The anode is treated in a special manner so as to render it non-porous and impervious to attack by the nascent chlorine evolved on its surface. No anode appears ever to have been invented that is at all suitable for working on a large scale, and the successful introduction of this compound anode, therefore, constitutes a marked advance in the apparatus used in electrolytic methods of production.

The apparatus by which the new process is being successfully demonstrated on a working scale has been put up by the Caustic Soda and Chlorine Syndicate, London, and has been in operation for several months past. The installation consists of five large electrolytic vessels, each of which is fitted up with five anodes and six cathodes arranged alternately. The anodes and cathodes are separated by the special diaphragms, and each vessel is thus divided into ten anode or chlorine sections and ten cathode or caustic soda sections. The anodes and cathodes in each vessel are connected up in parallel similar to an ordinary storage battery, but the five electrolytic vessels are connected up in series. The current is produced by an Elwell-Parker dynamo, and the electromotive force required to overcome the resistance of each vessel is about 4.4 volts, with a current density of 10 amperes per square foot of electrode surface. The anode sections, numbering fifty altogether, are connected by means of tubes, the inlet being at the bottom and the outlet at the top of each section. The whole of the cathode sections are connected in the same manner. In commencing operations, the electrolytic vessels are charged with a solution of common salt, through which a current of electricity is then passed, thus decomposing or splitting up the salt into its elements, chlorine and sodium. In the separation of the sodium, however, a secondary action takes place, which converts it into caustic soda. An automatic circulation of the solutions is maintained by placing the charging tanks at a slight elevation, and the vessels themselves on platforms arranged in steps. The solutions are pumped back from the lowest vessel to their respective charging tanks, the salt solution to be further decomposed and the caustic soda solution to be further concentrated. The chlorine gas evolved in the fifty anode sections is conveyed by means of main and branch tubes into several absorbers, in which milk of lime, kept in a state of agitation, takes up the chlorine, thus making it into bleaching or chlorate liquor as may be required. If the chlorine is required to be made into bleaching powder, then it is conveyed into leaden chambers and treated with lime in the usual manner. The caustic soda formed in the fifty cathode sections is more or less concentrated according to the particular purpose for which it may be required. If, however, the caustic soda is required in solid form, and practically free from salt, then the caustic alkaline liquor is transferred from the electrolytic vessels to evaporating pans, where it is concentrated to the required strength by evaporation and at the same time the salt remaining in the solution is eliminated by precipitation.

Such is the method of manufacturing caustic soda and chlorine by this process, which will doubtless have a most important bearing upon many trades and manufactures, more particularly upon the paper, soap, and bleaching industries. But the invention does not stop where we have left it, for it is stated that the process can be applied to the production of sodium amalgam and chlorine for extracting gold and other metals from their ores. It can also be utilized in the production of caustic and chlorate of potash and other chemicals, which can be manufactured in a state of the greatest purity. A very important consideration is that of cost, for upon this depends commercial success. It is therefore satisfactory to learn that the cost of production has been determined by the most careful electrical and analytical tests, which demonstrate an economy of over 50 per cent. as compared with present methods. Highly favorable reports on the process have been made by Dr. G. Gore, F.R.S., the eminent authority on electro-chemical processes, by Mr. W.H. Preece, F.R.S., and by Messrs. Cross & Bevan, consulting chemists. Dr. Gore states that the chemical and electrical principles upon which this process is based are thoroughly sound, and that the process is of a scientifically practical character. Should, however, the economy of production even fall somewhat below the anticipations of those who have examined into the process very carefully, it can hardly fail to prove as successful commercially as it has scientifically.

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COMPLETION OF THE MERSEY TUNNEL RAILWAY.

On the 11th of January (says the _Liverpool Daily Post_) will be opened for traffic the new station of the Mersey Tunnel Railway at the bottom of Bold Street. With the completion of the station at Bold Street the scheme may be said to have been brought successfully to a conclusion. It was not until 1879, after the expenditure of 125,000_l._ upon trial borings, that the promoters ventured to appeal to the public for support, and that a company, of which the Right Hon. H. Cecil Raikes, M.P., was chairman, was formed for carrying the project of the Mersey Railway into effect. The experience of the engineers in the construction of the tunnel is not a little curious. It was proved by the borings that the position in which the tunnel was proposed to be bored was not only the most important from the point of view of public convenience, and therefore of commercial advantage, but was from the point of view of engineering difficulty decidedly the most preferable. In this position the cuttings passed through the sandstone rock, although on the Liverpool side the shafts were sunk through a considerable depth through "made" ground, the whole of Mann Island and the Goree being composed of earth and gravel tipped on the old bank of the river. Indeed the miners passed through the cellars of old houses and unearthed old water pipes; excavated through a depth of tipped rubbish on which these houses had evidently been built; and then came upon the former strand of the river, beneath which was the blue silt usually found; then a stratum of bowlder clay; and finally the red sandstone rock. Once begun, the works were pushed forward night and day, Sundays excepted, until January, 1884, when the last few feet of rock were cleared away by the boring machine, and the mayors of Liverpool and Birkenhead met in fraternal greeting beneath the river. The operations gave employment to 3,000 men working three shifts of eight hours each, but were greatly accelerated by the use of Colonel Beaumont's boring machine, on which disks of chilled iron are set in a strong iron bar made to revolve by means of compressed air. This machine scooped out a tunnel 7 feet in diameter; and by successive improvements Colonel Beaumont attained a speed of 150 feet per week, leaving the old method of blasting far behind. As the machine moved forward the rock behind was broken out to the size of the main tunnel and bricked in in short lengths. One remarkable circumstance in connection with the work is that the boring from the Birkenhead side and the boring from Liverpool were found, when they were completed and joined, to be out of line by only 1 inch.

This excellent result was attained by careful calculations and experiments with perpendicular wires kept in position by weights, which, to avoid oscillation, were suspended in buckets of water. From shaft to shaft the tunnel is 1,770 yards in length and 26 feet in diameter; but for a length of 400 feet at the James Street and Hamilton Square stations the arch is enlarged to 501/2 feet. The tunnel is lined with from six to eight rings of solid brickwork embedded in cement, the two inner rings being blue Staffordshire or Burnley bricks. For the purpose of ventilation a smaller tunnel, 7 feet in diameter, was bored parallel with the main tunnel, with which it is connected in eight places by cross cuts, provided with suitable doors. Both at Liverpool and at Birkenhead there are two guibal fans, one 40 feet and the other 30 feet in diameter. The smaller, which throw each 180,000 cubic feet of air per minute, ventilate the continuations of the tunnel under Liverpool and Birkenhead respectively, and the larger tunnel under the river. The fans remove together 600,000 cubic feet of air per minute, and by this combined operation the entire air in the tunnel is changed once in every seven minutes. By the use of regulating shutters the air passes in a continuous current and the fans are noiseless. The telegraph and telephone wires pass through the tunnel, thus avoiding the long detour by Runcorn. Probably, as a feat of engineering, the construction of the new station at Bold Street is not inferior to any part of the scheme advanced. Under very singular and perplexing difficulties it could only be proceeded with in its first stages from midnight until six o'clock the following morning, it being of course essential that the traffic at the Central Station should not be interfered with. During these hours, night after night, trenches were cut at intervals of 10 feet across the roadway connecting the arrival platforms at the station, and into these were placed strong balks of timber, across which planks were laid as a temporary roadway. Beneath these planks, which were taken up and put down as required, the rock was excavated to a depth of 9 feet, and the balks supported upon stout props. Then from the driftway or rough boring beneath well holes were bored to the upper excavation, and through them the strong upright iron pillars designed to support the roof of the new tunnel station were passed, bedded and securely fixed in position. No sooner were they _in situ_ than the most troublesome part of the task was entered upon, for the balks had then to be removed in order to allow to be placed in position the girders running the length of the new station, and resting on the tops of the upright pillars. From these longitudinal girders cross girders of great strength were placed, and between these were built brick arches, packed above with concrete. This formed the roof of the new station. One portion of it passed under the rails in the station above, and had to be constructed without stoppage of the traffic. The rails had consequently to be supported on a temporary steel bridge of ingenious design, constructed by Mr. C.A. Rowlendson, the resident engineer and manager of the company, under whose personal supervision, as representing Sir Douglas Fox, the work has been carried out. With this device the men were enabled to go on in safety although locomotives were passing immediately above their heads. After the completion of the roof the station below was excavated by what is technically called "plug and feather" work--that is to say, by drilling holes into which powerful wedges are driven to split the rock.

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A STEAM STREET RAILWAY MOTOR.

While in Paris, President Yerkes, of the North Chicago Street Railway Company, purchased a noiseless steam motor, the results in experimenting with which will be watched with great interest. The accompanying engraving, for which we are indebted to the _Street Railway Review_, gives a very accurate idea of the general external appearance. The car is all steel throughout, except windows, doors and ceiling. It is 12 ft. long, 8 ft. wide, and 9 ft. high, and weighs about seven tons. The engines, which have 25 horse power and are of the double cylinder pattern, are below the floor and connected directly to the wheels. The wheels are four in number and 31 in. in diameter. The internal appearance and general arrangement of machinery, etc., is about that of the ordinary steam dummy. It will run in either direction, and the exhaust steam is run through a series of mufflers which suppress the sound, condense the steam and return the water to the boiler, which occupies the center of the car. The motor was built in Ghent, Belgium, and cost about $5,000, custom house duties amounting to about $2,000 more.--_The Railway Review_.

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TWENTY-FOUR KNOT STEAMERS.

Probably the most important form of steam machinery is the marine engine, not only because of the conditions under which it works, but because of the great power it is called upon to exert. Naturally its most interesting application is to Atlantic steaming. The success of the four great liners, Teutonic, Majestic, City of Paris and City of New York, has stimulated demand, and the Cunard Company has resolved to add to its fleet, and place two ships on the Atlantic which will outstrip the racers we have named.

The visitor to the late Naval Exhibition interested in shipping will have remarked at each of the several exhibits of the great firms a model of a projected steamer, intended to reduce the present record of the six days' voyage across the Atlantic--the _ne plus ultra_ at this time of steam navigation. To secure this present result a continuous steaming for the six days at 20 knot speed is requisite, not to mention an extra day or two at each end of the voyage. The City of Paris and the City of New York, Furst Bismarck, Teutonic and Majestic are capable of this, with the Umbria and Etruria close behind at 18 to 19 knots. Only ten years ago the average passage, reckoned in the same way as from land to land--or Queenstown to Sandy Hook--was seven days with a speed of 17 knots, the performance of such vessels as the Arizona and Alaska. Twenty years ago the length of the voyage was estimated as seven and a half to eight days at a speed of 16 knots, the performance of such vessels as the Germanic and Britannic of the White Star fleet of 5,000 tons and 5,000 horse power. Thirty years ago the paddle steamer was not yet driven off the ocean, and we find the Scotia crossing in between eight and nine days, at a speed of 13 or 14 knots. In 1858 ten and a half to twelve and a half days was allowed for the passage between Liverpool and New York. So as we recede we finally arrive at the pioneer vessels, the Sirius and Great Western, crossing in fourteen to eighteen days at a speed of 6 to 8 knots. For these historical details an interesting paper may be consulted, "De Toenemende Grootte der Zee-Stoombooten," 1888, by Professor A. Huet, of the Delft Polytechnic School.

Each of the last two or three decades has thus succeeded, always, however, with increasing difficulty, in knocking off a day from the duration of the voyage. But although the present six-day 20 knot boats are of extreme size and power, and date only from the last two or three years, still the world of travelers declares itself unsatisfied. Already we hear that another day must be struck off, and that five-day steamers have become a necessity of modern requirements, keeping up a continuous ocean speed of 231/2 knots to 24 knots. Shipbuilders and engineers are ashamed to mention the word _impossible_; and designers are already at work, as we saw in the Naval Exhibition, but only so far in the model stage; as the absence of any of the well known distinguishing blazons of the foremost lines was sufficient to show that no order had been placed for the construction of a real vessel. It will take a very short time to examine the task of the naval architect required to secure these onerous and magnificent conditions, five days' continuous ocean steaming at a speed of 24 knots.

The most practical, theory-despising among them must for the nonce become a theorist, and argue from the known to the unknown; and, first, the practical man will turn--secretly perhaps, but wisely--to the invaluable experiments and laws laid down so clearly by the late Mr. Froude. Although primarily designed to assist the Admiralty in arguing from the resistance of a model to that of the full size vessel, the practical man need not thereby despise Froude's laws, as he is able to choose his mode: to any scale he likes, and he can take his experiments ready made by practice on a large scale, as Newton took the phenomena of astronomy for the illustration of the mechanical laws. Suppose then he takes the City of Paris as his model, 560 ft. by 63 ft., in round numbers 10,000 tons displacement, and 20,000 horse power, for a speed of 20 knots, with a coal capacity of 2,000 tons, sufficient, with contingencies, for a voyage of six to eight days. Or we may take a later 20 knot vessel, the Furst Bismarck, 500 ft. by 50ft., 8,000 tons, and 16,000 horse power, speed 20 knots, and coal capacity 2,700 tons, to allow for the entire length of voyage to Germany.

In Froude's method of comparison the laws of mechanical similitude are preserved if we make the displacements of the model and of its copy in the ratio of the sixth power of the speeds designed, or the length as the square of the speed. Our new 24 knot vessel, taking the City of Paris as a model, would therefore have 10,000 (24 / 20)^{6} = 29,860, say 30,000 tons displacement, and would be 800 ft. x 90 ft. in dimensions. The horse power would have to be as the _seventh_ power of the speed, and our vessel would therefore have 20,000 (24 / 20)^{7}, or say 72,000 horse power. Further applications of Froude's laws of similitude will show that the steam pressure and piston speed would have to be raised 20 per cent., while the revolutions were discounted 20 per cent., supposing the engines and propellers to be increased in size to scale. To provide the requisite enormous boiler power, all geometrical scale would disappear; but it would carry us too far at present to follow up this interesting comparison.

Our naval architect is not likely at present to proceed further with this monstrous design, exceeding even the Great Eastern in size, if only because no dock is in existence capable of receiving such a ship. He has however learned something of value, namely, that this vessel, if the proper similitude is carried out, is capable of keeping up a speed of 24 knots for five days with ample coal supply, provided the boilers are not found to occupy all the available space. For it is an immediate consequence of Froude's laws that in similar vessels run at corresponding speeds over the same voyage, the coal capacity is proportionately the same, or that a ton of coal will carry the same number of tons of displacement over the same distance. Thus our enlarged City of Paris would require to carry about 4,000 tons of coal, burning 800 tons a day.

With the Britannic and Germanic as models of 5,000 tons and 5,000 horse power at 16 knot speed, the 24 knot vessel would require to be of 57,000 tons and 85,000 horse power, to carry sufficient coal for the voyage of 3,000 miles. These enormous vessels being out of the question, the designer must reduce the size. But now the City of Paris will no longer serve as a model, he must look elsewhere for a vessel of high speed, and smaller scale, and naturally he picks out a torpedo boat at the other end of the scale. A speed of 24 knots--and it is claimed even of 25, 26, and 27 knots--has been attained on the mile by a torpedo boat. But such a performance is useless for our mode of comparison, as sufficient fuel at this high speed for ten or twelve hours only at most can be carried--a voyage of, say, 500 miles; while our steamer is required to carry coal for 3,000 miles. The Russian torpedo boat Wiborg, for instance, is designed to carry coal for 1,200 miles at 10 knot speed; but at 20 knots this fuel would last only twenty-seven hours, carrying the vessel 540 miles. It will now be found that with this limited coal capacity the speed of the ordinary torpedo boat must be reduced considerably below 10 knots for it to be able to cross the Atlantic, 3,000 miles under steam. So that, even at a possible speed of 10 knots for the voyage, the full sized 24 knot five-day vessel, of which the best torpedo boat is the model, must have (2.4)^{6}, say 200 times the tonnage, and (2.4)^{7}, or 460 times the horse power. The enlarged Wiborg would thus not differ much from the enlarged City of Paris. A better model to select would be one of the recent dispatch boats, commerce destroyers, or torpedo catchers, recently designed by Mr. W.H. White, for our navy--the Intrepid or Endymion, for instance. The Intrepid is 300 ft. by 44 ft., 3,600 tons, and 9,000 horse power for 20 knot speed, with 800 hours' coal capacity for 8,000 miles at 10 knot speed; which will reduce to 3,000 miles at 16 knots, and 2,000 miles at 20 knots.

The Endymion is 360 ft. by 60 ft., with coal capacity for 2,800 miles at 18 knot speed, or for about 144 hours or six days. The enlarged Endymion for the same voyage of 2,800 miles in five days, or at 211/2 knot speed, would be 44 per cent larger and broader, that is 520 ft. by 86 ft., and of threefold tonnage, and three and a half times, or about 30,000 horse power--about the dimensions of the Furst Bismarck, but much more powerfully engined. This agrees fairly with the estimate in the SCIENTIFIC AMERICAN of 19th Sept, 1891., where it is stated that twenty-two boilers, at a working pressure of 180 lb. on the square inch, would be required, allowing 11/2 lb. of coal per horse power hour.

The Intrepid, enlarged to a 24 knot boat, for the same length of voyage of 3,000 miles, would be 650 ft. by 100 ft., 40,000 tons, and about 45,000 horse power. So now we are nearing the Messrs. Thomson design in the Naval Exhibition of the five-day steamer, 231/2 knot speed, 630 ft. by 73 ft., and 30,000 to 40,000 horse power.

No one doubts the ability of our shipbuilding yards to turn out these monsters; and on the measured mile, and for a good long distance, we shall certainly see the contract speeds attained and some excelled. But the whole difficulty turns on the question of the coal capacity, and whether it is sufficient to last for even five days or for 3,000 miles. Every effort then must be made to shorten the length of the voyage from port to port; and we may yet see Galway and Halifax, only 2,200 miles apart, once more mentioned as the starting points of the voyage as of old, in the earliest days of steam navigation. In those days the question of fuel supply was a difficulty, even at the then slow speeds, in consequence of the wasteful character of the engines, burning from 7 lb. of coal and upward per horse power hour. Dr. Lardner's calculations, based upon the average performance of those days, justified him in saying that steam navigation could not pay--as was really the case until the introduction of the compound engine.

It is recorded in Admiral Preble's "Origin and Development of Steam Navigation," Philadelphia, 1883, page 160, that the Sirius, 700 tons and 320 horse power, on her return voyage had to burn up all that old be spared on board, and took seventeen days to reach Falmouth. An interesting old book to consult now is Atherton's "Tables of Steamship Capacity," 1854, based as they are upon the performance of the marine engine of the day. Atherton calculates that a 10,000 ton vessel could at 20 knots carry only 204 tons of cargo 1,676 miles, while a 5,000 ton vessel at 18 knots on a voyage of 3,000 miles could carry no cargo at all. Also that the cost per ton of cargo at 16 knots would be twenty times the cost at eight knots, implying a coal consumption reaching to 12 lb. per horse power hour. It is quite possible that some invention is still latent which will enable us to go considerably below the present average consumption of 2 lb. to 11/2 lb. per horse power hour; but at present our rate of progress appears asymptotic to a definite limit.

To conclude, the whole difficulty is one of fuel supply, and it is useless to employ a fast torpedo boat as our model, except at the speed at which the torpedo boat can carry her own fuel to cross the Atlantic. If the voyage must be reduced in time, let it be reduced from six days to four, by running between Galway and Halifax, a problem not too extravagant in its demands for modern engineering capabilities. A statement has recently gained a certain amount of circulation to the effect that the Inman Company was about to use petroleum as fuel, in order to obtain more steam. We have the best possible authority for saying there is not the least syllable of truth in this rumor. It has also been stated that since solid piston valves have been fitted to the Teutonic in lieu of the original spring ring valves, she has steamed faster. This rumor is only partially true. Her record, outward passage, of 5 days 16 hours 31 minutes, was made on her previous voyage. She has, however, since made her three fastest trips homeward.--_The Engineer_.

* * * * *

THE MILITARY ENGINEER AND HIS WORK.[1]

By Col. W.R. KING.

[Footnote 1: A lecture delivered before the students of Sibley College, Cornell University, December 4, 1891.--_The Crank_.]

It is not an easy matter to present a dry subject in such an attractive form as to excite a thrilling interest in it, and military science is no exception to this rule. An ingenious military instructor at one of our universities has succeeded in pointing out certain analogies between grand tactics and the festive game of football, which appears to have greatly improved the football, if we may judge from the recent victories of the blue over the red and the black and orange, but it is not so clear that the effect of the union has been very beneficial to military science; and even if such had been the case, I fear there are no similar analogies that would be useful in enlivening the subject of military engineering.

From the earliest times of which we have record man has been disposed to strive with his fellow man, either to maintain his own rights or to possess himself of some rights or material advantage enjoyed by others. When one or only a few men encroach on the rights of others in an organized community, they may be restrained by the legal machinery of the state, such as courts, police, and prisons, but when a whole community or state rises against another, the civil law becomes powerless and a state of war ensues. It is not proposed here to discuss the ethics of this question, nor the desirability of providing a suitable court of nations for settling all international difficulties without war. The great advantage of such a system of avoiding war is admitted by all intelligent people. We notice here a singular inconsistency in the principles upon which this strife is carried on, viz.: If it be a single combat, either a friendly contest or a deadly one, the parties are expected to contest on equal terms as nearly as may be arranged; but if large numbers are engaged, or in other words, when the contest becomes war, the rule is reversed and each party is expected to take every possible advantage of his adversary, even to the extent of stratagem or deception. In fact, it has passed into a proverb that "all things are fair in love and war."

Now one of the first things resorted to, in order to gain an advantage over the enemy, was to bring in material appliances, such as walls, ditches, catapults, scaling ladders, battering rams, and subsequently the more modern appliances, such as guns, forts, and torpedoes, all of which are known as engines of war, and the men who built and operated these engines were very naturally called engineers. It is this kind of an artificer that Shakespeare refers to when he playfully suggests that "'tis the sport to have the engineer hoist with his own petard."

The early military engineer has left ample records and monuments of his genius. The walls of ancient cities, castles that still crown many hills in both hemispheres, the great Chinese wall, the historical bridge of Julius Caesar, which with charming simplicity he tells us was built because it did not comport with his dignity to cross the stream in boats, the bridge of boats across the Hellespont, by Xerxes, are all examples of early military engineering. The Bible tells us "King Uzziah built towers at the gates of Jerusalem, and at the turning of the wall, and fortified them." We may note in passing that the buttresses, battlements, and bartizans with which our modern architects ornament or disfigure churches, peaceful dwellings, and public buildings, are copied from the early works of the military engineer.

Coming down to the military engineers of our own country, we find that one of the first acts of the Continental Congress, after appointing Washington as commander-in-chief, was to authorize him to employ a number of engineers. It was not, however, until 1777 that a number of engineer officers from the French army arrived in this country, and were appointed in the Continental army. General DuPortail was made Chief Engineer, and Colonel Kosciusko, the great Polish patriot, was among his assistants. Other officers of the Continental army were employed on engineering duty; and under their supervision such works as the forts and the great chain barrier at West Point were built, and the siege operations around Boston and Yorktown were carried on.

After the close of the war, in 1794, a Corps of "Artillerists and Engineers" was organized. This corps was stationed at West Point, and became the nucleus of the United States Military Academy. In 1802, by operation of the law reorganizing the army, this corps was divided, as the names would indicate, into an Artillery Corps and Corps of Engineers. The Corps of Engineers consisted of one major, two captains, four lieutenants, and ten cadets. The Artillery Corps was again divided into the Ordnance Corps and several regiments of artillery, now five in number, while the duties of the Corps of Engineers were divided between the Engineer Corps and a Corps of Topographical Engineers, organized at a later date; but on the breaking out of the late rebellion it was deemed best to unite the two corps, and they have so remained until the present time. The Corps of Engineers now consists of 118 officers of various grades, from second lieutenant to brigadier general, of which last grade there is only one officer, the chief of the corps, and it requires something more than an average official lifetime for the aforesaid lieutenant to attain that rank. Hardly one in ten of them ever reach it. Daniel Webster's remark to the young lawyer, that "there is always room at the top," will not apply to the Corps of Engineers. The officers are all graduates of the Military Academy, which institution continued as a part of the Corps of Engineers until 1866. The vacancies in the corps are filled by the assignment to it of from two to six graduates each year, and there is attached to the corps a battalion of four companies of enlisted men, formerly called Sappers and Miners, but now known as the Battalion of Engineers.

We now come naturally to the duties of our military engineer, and here I may remark that these duties are so varied and so numerous that a detailed recital of them would suggest Goldsmith's "Deserted Village:"

... "And still the wonder grew
That one small head could carry all he _ought to know_"

[Never lose sight of fact for the sake of rhyme.]

In general terms, his duties consist of:

1. Military surveys and explorations.

2. Boundary surveys.

3. Geodetic and hydrographic survey of the great lakes.

4. Building fortifications--both permanent works and temporary
or field works.

5. Constructing military roads.

6. Pontoniering or building military bridges, both with the
regular bridge trains and with improved materials.

7. The planning and directing of siege operations, either
offensive or defensive; sapping, mining, etc.

8. Providing, testing and planting torpedoes for harbor
defense when operating from shore stations.

9. Staff duty with general officers.

10. Improving rivers and harbors.

11. The building and repairing of lighthouses.

12. Various special duties as commissioner of District of
Columbia, superintendent military academy, commandant engineer
school, instructors at both of these schools, attaches to
several foreign legations, for the collection of military
information, etc.

It would, of course, exceed the proper limits of a single lecture to go into the details of these many duties, but we may take only a passing glance at most of them, and give more special attention to a few that may involve some points of interest. Perhaps the most interesting branch of the subject would be that of permanent fortifications, or what amounts to almost the same thing in this country, sea coast defenses. And here our trouble begins, for, while civil engineers have constant experience to guide them, their roads, bridges, and other structures being in constant use, the military engineer has only now and then, at long intervals, a war or a siege of sufficient extent to furnish data upon which he can safely plan or build his structures. Imagine a civil engineer designing a bridge, road, or a dam to meet some possible future demand, without having seen such a structure used for twenty years or more, and you can form some estimate of the delightful uncertainties that surround the military engineer when called upon to design a modern fort. The proving ground shows him that radical improvements are necessary, but actual service conditions are almost entirely wanting, and such as we have contradict many of the proving ground theories. Thus we have the records of shot going through 25 inches of iron or 25 feet of concrete on the proving ground; but such actual service tests as the bombardment of Fort Sumter, Fort Fisher, and the forts at Alexandria contradict this entirely, and indicate that, except for the moral effect, our old forts, with modern guns in them and some additional strengthening at their weaker points, would answer all purposes so far as bombardment from fleets is concerned. This is not saying that the forts are good enough in their present condition, but simply that they can readily be made far superior in strength, both offensive and defensive, to any fleet that could possibly be provided at anything like the same expense, or in fact at any expense that would be justified by the condition of our treasury, either past, present, or probable future. It might be added that a still more serious difficulty in the way of the military engineer, so far as practice and its consequent experiences are concerned, is that for many years past, until quite recently, there have been no funds either for experiments or actual work on fortifications, so that very little has been done on them during the last twenty years.

Without going into the question of the necessity for sea coast defenses, we may assume that an enemy is likely to come into one of our harbors and that it is desirable to keep him out. What provisions must be made to accomplish this, i.e., to secure the safety of the harbors and the millions of dollars' worth of destructible property concentrated at the great trade centers that are usually located upon those harbors? We must first take a look at the enemy and see what he is like before we can decide what will be needed to repel his attack. For this purpose we need not draw on the imagination, but we may simply examine some of the more recent armadas sent to bombard seaports. For example, the fleet sent by Great Britain to bombard the Egyptian city of Alexandria, in 1882. This fleet consisted of eight heavy ironclad ships of from 5,000 to 11,000 tons displacement and five or six smaller vessels; and the armament of this squadron numbered more than one hundred guns of all calibers, from the sixteen inch rifle down to the seven inch rifle, besides several smaller guns. But this fleet represented only a small fraction of England's naval power. During some recent evolutions she turned out thirty-six heavy ironclads and forty smaller vessels and torpedo boats. The crews of these vessels numbered nearly 19,000 officers and men, or about three times the entire number in our navy. Such a fleet, or, more likely, a much larger one, might appear at the entrance say of New York harbor within ten days after a declaration of war, and demand whatever the nation to which it belonged might choose, with the alternative of bombardment.

The problem of protecting our people and property from such attacks is not a new one, and, in fact, most of the conditions of this problem remain the same as they were fifty years ago, the differences being in degree rather than in kind. The most natural thought would be to meet such a fleet by another fleet, but the folly of such a course will become apparent from a moment's consideration. The difficulties would be:

1st. Our fleet must be decidedly stronger than that of the enemy, or we simply fight a duel with an equal chance of success or failure.

2d. In such a duel the enemy would risk nothing but the loss of his fleet, and even a portion of that would be likely to escape, but we would not only risk a similar loss, but we would also lose the city or subject it to the payment of a heavy contribution to the enemy.