Chapter XI: TECHNOLOGY--American Workshops.--The care of tools and practice (1)

in American workshops, as viewed from an English standpoint

New Sugar Items.--Interesting points in the cultivation of sugar
beets and manufacture of sugar therefrom in France, Germany,
and other countries

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THE GREAT BELL OF THE BASILICA OF THE SACRED HEART OF MONTMARTRE.

The main work on the basilica of the Sacred Heart is now completed and the bell tower surmounts it. So we have now a few words to say about "La Savoyarde"--the name of the great bell which is designed for it, and which has just been cast at Annecy-le-Vieux, in Upper Savoy, in the presence of Mgr. Leuilleux, Archbishop of Chambery, Mgr. Isoar, Bishop of Annecy, and of all the clergy united, at the foundry of Messrs. G. & F. Paccard, especially decorated for the occasion.

One of the Latin inscriptions that ornament the metal of "La Savoyarde" at once explains to us its name and tells us why a bell designed for the capital was cast at Annecy-le-Vieux. The following is a translation of it:

"In the year 1888, in the course of the solemnities of the
sacerdotal jubilee of the Sovereign Pontifex Leo XIII., I,
Frances Margaret of the Sacred Heart of Jesus, on the
initiative of Francis Albert Leuilleux, Archbishop of
Chambery, with the co-operation of the bishops of the
province, at the common expense of the clergy and upper and
lower classes of Savoy, was offered as a gift, as a
testimonial of piety toward the divine heart, in order to
repeat through the ages, from the top of the holy hill, to the
city, to the nation and to the entire world, 'Hail Jesus!'"

Let us now witness the casting of the bell.

Over there, at the back of the foundry, in the reverberatory furnace, the alloy of copper and tin, in the proportions of 78 and 22 per cent., is in fusion. From the huge crucible runs a conduit to the pit, at the side of which the furnace is constructed, and in which is placed the mould. A metallic plug intercepts communication. A quick blow with an iron rod removes this plug and the tapping is effected. This operation, which seems simple at first sight, is extremely delicate in practice and requires a very skillful workman. A host of technical words designates the dangers that it presents. Before the tapping, it is necessary to calculate at a glance the function of the gate pit. And what accidents afterward! But we need not dwell upon these. After the cooling of the metal comes the cleaning, which is done with scrapers and special instruments.

The casting is preceded by two operations--the designing and the moulding. The design rests upon a basis generally furnished by experience, and which the founders have transmitted from generation to generation. The thickness of the rim of the bell taken as unity determines the diameters and dimensions. The outline most usually followed gives 15 rims to the large diameter, 71/2 to the upper part of the bell, and 32 to the large radius that serves to trace the profiles of the external sides.

The moulding is done as follows: In the pit where the casting is to be done there is constructed a core of bricks and a clay shell, separated from each other by a thickness of earth, called false bell. This occupies provisionally the place of the metal, and will be destroyed at the moment of the casting.

Now let us give a brief description of "La Savoyarde." Its total weight is 25,000 kilogrammes, divided as follows: 16,500 kilogrammes of bronze, 800 kilogrammes for the clapper, and the rest for the suspension gear.

Its height is 3.06 meters and its width at the base is 3.03. It is therefore as high as it is wide, and, as may be seen from our engraving, two men can easily seat themselves in its interior. In weight, it exceeds the bell of Notre Dame, of Paris, which weighs 17,170 kilogrammes, that of the Cathedral of Sens, which weighs 16,230, and that of the Amiens bell, which weighs 11,000. But it cannot be compared to the famous bell given by Eudes Rigauit, Archbishop of Rouen, to the cathedral of that city, and which was so big and heavy that it was necessary to give a copious supply of stimulants to those who rang it, in order "to encourage" them.

"La Savoyarde" will appear small also if we compare it with some celebrated bells, that of the Kremlin of Moscow, for example, which weighs 201,216 kilogrammes. One detail in conclusion: "La Savoyarde" sounds in counter C. This had been desired and foreseen. The number of vibrations, that is to say, the _timbre_ of a bell, is in inverse ratio of its diameter or of the cubic root of its weight, so that in calculating the diameters and in designing "La Savoyarde" the _timbre_ was calculated at the same time.--_L'Illustration._

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[FROM THE SUGAR BEET.]

NEW SUGAR ITEMS.

FRANCE.

Water that has been used to wash frozen beets contains a small percentage of sugar. As the washing period, in such cases, is longer than with normal beets, the sugar in beet cells has time to pass through the outer walls by osmosis. The sugar loss is said to be 0.66 per cent. (?) of the weight of beets washed.

Well conducted experiments show that in small but well ventilated silos, beets lose considerable weight, but very little sugar. On the other hand, in large silos with poor ventilation, the sugar loss frequently represents four to six per cent. When fermentation commences, the mass of roots is almost ruined.

Sodic nitrate, if used upon soil late in the season, may overcome a difficulty that has been recently noticed. Beet fields located near swamps that are dry a portion of the year have suffered from a malady that turns leaves from green to yellow, even before harvesting period; such beets have lost a considerable amount of sugar.

A new method for the analysis of saccharose and raffinose, when in the presence of inverted sugar, is said to give accurate results. The process consists in adding sulphate of copper and lime to hot molasses, so that the oxide of copper is changed to a protoxide, and the invert sugar becomes water and carbonic acid. The whole is neutralized with phosphoric acid. There follow a great number of precipitates; the exact volume of liquid in which these are found is determined after two polariscopic observations.

It has been constantly noticed that samples of carbonatated juice vary in composition with the part of tank from which they are taken. If some arrangement could be made assuring a thorough mixing during the passage of carbonic acid, results would be more satisfactory than they now are. If gas could be distributed in every part of the tank, the lime combination could be made perfect.

Notwithstanding the new law regulating quantity of sugar to be used in wines, ciders, etc., there has been, during 1890, an increase of nearly 13,000 tons, as compared with 1889. Consumption of sugar for these special industries was 33,000 tons; alcohol thus added to wine was about 71,000,000 gallons.

Beets cultivated without extra fertilizers, and that are regular in shape and in good condition, without bruises, are the ones which give the best results in silos. It is recommended to construct silos of two types; one which is to be opened before first frost, the other where beets remain for several months and are protected against excessive cold. Great care should be taken that a thorough ventilation be given in the first mentioned type. In the other, more substantial silos, ventilation must be watched, and all communication with the exterior closed as soon as the temperature falls to or near freezing.

During the last campaign many manufacturers experienced great difficulty in keeping the blades of slicers sufficiently sharp to work frozen beets. Sharpening of blades is an operation attended to by special hands at the factory; and under ordinary circumstances there need be no difficulty. However, it is now proposed to have central stations that will make a specialty of blade sharpening. Under these circumstances manufacturers located in certain districts need give the matter no further thought, let the coming winter be as severe as it may.

Some success has been obtained by the use of sulphurous acid in vacuum pans. Great care is required; the operation cannot be done by an ordinary workman. It is claimed that graining thereby is more rapid and better than is now possible. Chemists agree that the operation is more effectual by bringing sulphurous acid in contact with sirups rather than juices; it is in the sirups that the coloring pigments are found. Sulphurous acid is run into the pan until the sirups cover the second coil. In all cases the work must be done at a low temperature.

Height of juice in carbonatating tanks is only three feet in France, while in Austria it is frequently twelve feet. The question of a change in existing methods is being discussed; it necessitates an increase in the blowing capacity of machine; since carbonic acid gas has a greater resistance to overcome in Austrian than in French methods. Longer the period juices are in contact with carbonic acid, greater will be the effect produced.

Ferric sulphate has been very little used for refuse water purification, owing to cost of its manufacture. If roasted pyrites, a waste product of certain chemical factories, are sprinkled with sulphuric acid of 66 deg. B., and thoroughly mixed for several hours, at a temperature of 100 deg. to 156 deg. F., the pyrites will soon be covered with a white substance which is ferric sulphate. Precipitates from ferric sulphate, unlike calcic compounds, do not subsequently enter into putrefaction.

Efforts are being made to convince manufacturers of the mistake in using decanting vats, in connection with first and second carbonatation. In Germany filter presses are used, decanting vats are obsolete. The main objection to them is cooling of saccharine liquors, which means an ultimate increase in fuel. Cooling is frequently followed by partial fermentation.

Further changes in the proposed combined baryta-soda method for juice purification consist in using powdered soda carbonate 90-92 deg., upon beet cossettes as they leave the slicer, before entering the diffusor. The quantity of chemical to be used is 1/1000 of weight of beet slices being treated. If a diffusor has a capacity of 2,500 lb., there would be added 2.5 lb. soda carbonate. From the diffusor is subsequently taken 316 gallons juice at 4-5 deg. density, this is rapidly heated to 185 deg.F., then 2.4 of a pure baryta solution is added; temperature is kept at 185 deg. F. for a short time; resulting precipitates fall to bottom of tank; then 13 gallons milk of lime 25 deg. B. are added.

Other operations that follow are as usual. It is contended that the cost of baryta is 10 cents per ton beets worked. The most important advantage is gain in time; a factory working 20,000 during a 100-day campaign, by the foregoing process can accomplish the same work in 80 days, thus decreasing wear and tear of plant and diminishing percentage of sugar lost in badly constructed silos.

The exact influence of a low temperature upon beet cells has never been satisfactorily settled. Considerable light has recently been thrown upon the subject by a well known chemist. It is asserted that living cells containing a saccharine liquid do not permit infiltration from interior to exterior; this phenomenon occurs only when cell and tissue are dead. It is necessary that the degree of cold should be sufficiently intense, or that a thaw take place, under certain conditions, to kill tissue of walls of said cells. An interesting fact is that when cells are broken through the action of freezing, it is not those containing sugar that are the first affected. The outer cells containing very little sugar are the first to expand when frozen, which expansion opens the central cells.

Experiments to determine the action of lime upon soils apparently prove that it does not matter in what form calcic salts are employed; their effect, in all cases, is to increase the yield of roots to the acre. On the other hand, very secondary results were obtained with phosphoric and sulphuric acids.

A micro-mushroom, a parasite that kills a white worm, enemy of the beet, has been artificially cultivated. As soon as the worm is attacked, the ravage continues until the entire body of the insect is one mass of micro-organisms. Spores during this period are constantly formed. If it were possible to spread this disease in districts infected by the white worm, great service could be rendered to beet cultivation.

In sugar refining it is frequently desirable to determine the viscosity of sirups, molasses, etc. Methods founded upon the rapidity of flow through an orifice of a known size are not mathematical in their results. A very simple plan, more accurate than any hitherto thought of, is attracting some attention. Sensitive scales and a thermometer suspended in a glass tube are all the apparatus necessary. The exact weight of thermometer, with tube, is determined; they are immersed in water and weighed for the second time; the difference in weight before and afterward gives the weight of adhering water. If the operation is repeated in molasses, we in the same way obtain the weight of adhering liquid, which, if divided by the weight of adhering water, gives the viscosity as compared with water.

Sugar refineries located at Marseilles claim that it is cheaper for them to purchase sugar in Java than beet sugar of northern Europe. On the other hand, the argument of Paris refiners is just the reverse. The total refined sugar consumed is 375,000 tons, the colonial and indigenous production of raw sugar is nearly 1,000,000 tons more than sufficient to meet the demands of the entire refining industry of the country. There appears to have been considerable manipulation, foreign sugar being imported with the view of producing a panic, followed by a decline of market prices, after which Marseilles refiners would buy. All sound arguments are in favor of protecting the home sugar industry.

It has been suggested that manufacturers weigh the fuel used more carefully than hitherto; the extra trouble would soon lead to economy for all interested in sugar production at ruinous cost. Some chemists advocate that coal be purchased only after having been analyzed. Efforts to have a unification in methods of analysis of all products of factory is a move in the right direction; the Association of Sugar Chemists have adopted a series of methods that are in the future to be considered as standard.

Copper solutions are destined to render great service in the destruction of micro-organisms that attack the beet field. The liquid used should be composed of 3 per cent. copper sulphate and 3 per cent. lime, dissolved in water; fifty gallons are sufficient for one acre; cost per acre, every item included, is 56 cents. The normal vitality of the plant being restored, there follows an increased sugar percentage. Ordinary liquid ammonia may be advantageously used to kill white worms and insects that attack beets; two quarts of the diluted chemical are used per square yard, and the cost is $12 per acre (?)

GERMANY.

Calcic salt elimination from beet juices is a problem not yet satisfactorily solved. Since the early history of beet sugar making, it has been noticed that calcic salts render graining in the pan most tedious; hence repeated efforts to reduce to a minimum percentage the use of lime during defecation. In all cases it is essential to get rid of inverted sugar. The difficulty from excess of lime is overcome by adding it now and then during carbonatation; but other means are found desirable; and phosphoric acid, magnesia, soda, etc., have been used with success. Recent observations relating to the action of soda upon calcic sulphates, calcic glucates, etc., are most important. Certain citrates have a retarding influence upon calcic sulphates.

An alarm contrivance to announce the passage of juices into condensing pipes has rendered considerable service in beet sugar factories.

A process for refining sugar in the factory, at less cost than it is possible to make raw sugar by existing processes, deserves notice. Sugars by this new method test 99.8, and sirups from the same have a purity coefficient of 70. Weight of dry crystals obtained is said to represent 66 per cent. of _masse cuite_ used. The additional cost of the process is $30 to $40 per centrifugal. Concentrated juice or sirup may be used as _cleare_ in centrifugals; this sirup should have a density of 1.325 (36 deg. B.) at 113 deg. to 122 deg. F., so as not to redissolve the sugar. Sirup should not be used until all adhering sirup of _masse cuite_ has been swung out. The sirup, after passing through centrifugals, may be sent to second carbonatation tanks and mixed with juices being treated.

The larva of an insect, known as _sylpha_, has attacked beet fields in several parts of Saxony. The effect upon the root is a decrease in foliage, followed by late development of the beet, with corresponding reduction in sugar percentage. Chickens may render excellent service, as they eat these worms with considerable relish. A solution of Schweinfurt green has been used with some success; its cost is $2.50 per acre. None of the chemical remains on the leaves after a rain (?) White worms have done some damage; they should be collected from the fields during plowing. When they become beetles in the spring, they may be destroyed by a solution of sulphide of carbon; $0.20 worth of this chemical is sufficient to kill 10,000 of them. These beetles contain 50 per cent of fatty and nitric elements; when pulverized they may be used as good for pigs and chickens. If the ground mass of beetles is sprinkled with sulphuric acid and a reasonable amount of lime and earth be added, the combination forms an excellent fertilizer for certain crops. A disease that blackens young beet leaves is found to be due to a microscopic insect. If the beet seed be saturated in a phenic solution before planting, the difficulty may be overcome.

We are soon to have a new method for selecting mothers for seed production. Details of the same are not yet public. It is claimed that it will be possible to grow seed that will yield beets of a given quality determined in advance, a problem which has hitherto been thought impossible.

It will surprise many of our readers to learn that if "tops" or even half beets are planted, they will give seed, the quality of which is about same; showing that as soon as seed stalks commence to appear, the _role_ of the root proper is of secondary consideration, as it serves simply as a medium between the beet and soil(?)

Sprayed water may be used with considerable success in washing sugar in centrifugals; it is claimed that this new process offers many advantages over either steam, water, or use of _cleare_. White sugar to be washed is thoroughly mixed with a sugar sirup supersaturated. The whole is run into centrifugals. The sirup swung from the same is used in next and following operations; when it becomes too thick it is sent to the vacuum pan to be regrained. The operation of washing lasts less than two minutes; three quarts of water are necessary for 200 lb. sugar. The water spray at a pressure of 5 to 10 atmospheres is produced by a very simple appliance.

Total weight of refuse cossettes obtained during last campaign was 4,000,000 tons, about 700,000 tons of which were sold for $1,000,000; if what remains is dried, it would be worth $5,000,000.

Several sodic-baryta methods have been recently invented. Of these we will mention one where 1/4000 to 1/2000 part of calcined soda is added to the beet slices in diffusors. The juice when drawn from the battery is heated to 154 deg. F., and defecated with hydrate of baryta and milk of lime. Nearly all foreign substances are thus eliminated. Carbonatation then follows.

Government taxation upon the sugar industry is destined within a few years to be withdrawn. The new law recently put into operation no longer taxes beets worked at factory, but the sugar manufactured. The rate of taxation is about 2 cents per pound on all sugar made.

Recent data from northeast Germany give the work during campaign 1890-91 of 54 associated beet sugar factories. They used 2,130,000 tons beets, obtained from 142,602 acres of land, average yield 12 tons. The total sugar amounted to 251,000 tons, of which 241,000 were from beets and 10,000 tons from molasses worked by special processes. The polarization of beet juices averaged 13.09; _masse cuite_, 14.31; extraction of sugar of all grades, 11.79. It required 848 lb. beets to produce 100 lb. sugar.

In every center where beet sugar is made there exists some local society; each year members from these societies meet to exchange views upon the sugar situation of the empire.

Of late, there has been a general complaint respecting quality of sugar sold on the Magdeburg market. At one time the sugars averaged more organic substances than ash; now there is more ash than organic substances. Such sugars are most difficult to work, and cause much loss of time in centrifugals.

The most desirable temperature for diffusion batteries is not yet definitely settled. Some manufacturers recommend 82 deg. to 86 deg. F. On the other hand, satisfactory results have been obtained at 145 deg. F., followed by cold water in the diffusors.

The use of hydrofluoric acid, even in small quantities to prevent fermentation, should not be allowed.

It is proposed to use hydrogen dioxide for saccharine juice purification. The alkalinity of juice is reduced to 0.07 by a judicious use of lime. Precaution must be taken to keep the temperature at 87 deg. F. After a preliminary filtration about 4 per cent. hydrogen dioxide is added. The whole is then heated to the boiling point, after which 1/2 to 1 per cent. lime is added. When alkalinity of filtrate is 0.03 phosphoric acid and magnesia are added, in quantities representing 0.03 per cent. of sugar in juice for magnesia, and 0.6 per cent. for the phosphoric acid. In working beet juices hydrogen dioxide may be used in the diffusor or during any phase of the sugar manufacturing process, even upon sugars in centrifugals. In all cases the results obtained are said to be most satisfactory.

A method to crystallize the sugar contained in the mother liquor of a _masse cuite_ consists in mixing during 24 hours the hot product, direct from the pan, with low grade molasses. Gradual cooling follows. The crystals of _masse cuite_ effect a crystallization of the otherwise inactive product contained in the molasses. The separation of crystals from adhering molasses is done in a special washing appliance arranged in battery form.

It has been frequently asked if the existing and accepted formula for determining in advance the amount of refined sugar that may be extracted from either beets, _masse cuite_ or raw sugar, is to be considered exact, without special allowance being made for raffinose. An intelligent discussion upon the subject shows that the sugar in question, whether present or not, in no way influences the formula under consideration.

AUSTRIA-HUNGARY.

The committee on exhibition at Prague has issued several interesting pamphlets, from which we learn that in Bohemia, in 1819, there existed one beet sugar factory. In 1890 the total number of factories was 140; last year 370,000 acres were planted in beets, and the yield was 3,700,000 tons; yield of sugar averaged 2,700 lb. per acre; 40,000 hands were employed. During the past 24 years 17,900,000 tons of coal have been consumed, and the working capacity per factory is now far greater than formerly. There are at present seven sugar refineries in Bohemia.

Commercial arrangements with Germany having terminated favorably, great pressure is being brought to bear upon Italy, Roumania, Servia and Switzerland, to induce them to enter into a treaty. Sugars imported by the country last named were 35,892 tons in 1889 and 43,300 tons during 1890.

BELGIUM.

If fresh cossettes are fed to cows, in quantities per diem representing 20 per cent. of the animal's weight, they have a thinning effect. When the refuse has been siloed for eight months, and 12 per cent. of the animal's weight is used, there will follow a slight daily increase in weight. Better results may be obtained from cossettes that have been kept for two years; with the latter, if cows eat only 7 per cent. of their weight, considerable fattening follows. Consequently, while beet refuse, after long keeping, loses 50 per cent. of its weight, it appears in the end to be more economical for feeding purposes than fresh cossettes direct from the battery.

During this period of keeping the percentage of water remains nearly constant; fatty substances which were 0.08 per cent. become 0.74; and the percentage of carbohydrates diminishes. Chemists are unable to explain the changes that have taken place; if they are desirable, as they appear to be, judging from the practical results just cited, there is this question to be solved: What future have dried cossettes? Evidently they offer advantages, as no one can doubt, such as a decrease in weight and bulk, easy keeping for an indefinite time, etc. At present, there is building a silo to contain 4,000 tons fresh cossettes; this is to have the best possible system of drainage. During the coming season it is proposed to analyze the water draining from this mass of fermenting refuse; and we may then learn more than we now know about the chemical changes above mentioned.

A correspondent of M. Sachs asks why it is not possible to use live steam in defecating tanks. A simple calculation shows that the water to be subsequently evaporated would be increased 10 per cent. This evaporation would cost more than cleaning of copper coils, etc., combined with other difficulties existing appliances offer.

The question as to the most desirable number of beets necessary to analyze to obtain an average has been in part settled. Factories working 500 tons per diem should make at least 200 analyses of beets received, which work offers no difficulty by the rapid methods now used. Several samples should be taken from every cart load delivered, then make average selections from the same.

RUSSIA.

Weak currents of electricity, 0.03 to 0.04 ampere, have been passed through sirups for fourteen hours without any special increase in purity coefficient. Experiments made upon diluted molasses or with raw beet juices were not encouraging.

Mixing of filter press scums with diffusion juices is said to offer special advantages for the preliminary purification. Not over one to two per cent. of scums should be used. If in too great quantity, the raw juices will yield inferior results. During operations that follow, experiments are not yet sufficiently advanced to determine with certainty within what limits the refuse scum utilization process is to be recommended. We have great doubts as to the wisdom of introducing foreign elements, eliminated from other juices in a previous operation, into a juice fresh from the battery.

OTHER COUNTRIES.

The beet sugar factory in Japan is said to be working with considerable success.

This year in Europe over 3,000,000 acres are devoted to beet cultivation. If the yield averages 12 tons, the crop of roots to be worked during campaign 1891-92 will certainly not be less than 36,000,000 tons, with a total yield of first grade sugar of about 7,300,000,000 lb.

Sugar sells for 9 cents per pound in Persia, where Russia has almost a monopoly of that business.

Finland imported, during 1889, 9,416 tons sugar, valued at $1,000,000. Germany supplied two-thirds of this at cheaper rates than Russia, owing to facilities of transportation. Two refineries are working; one of these uses exclusively cane sugar, while the other employs both cane and beet sugar.

A beet sugar factory in England, that has been idle for many years, is to resume operations under a new company, adopting the plan of growing a sufficient quantity of beets for an average campaign, independently of what all the farmers of the locality propose to do.

Siberia is to have a beet sugar factory. Experiments in beet cultivation have shown excellent beets may be raised there. Special advantages are offered by the Russian government, and factories are to be exempt from taxation daring a period of ten years. Sugar in Siberia is now considered an article of luxury, owing to distance and difficulties of transportation from manufacturing centers.

A special delegation from Canada has been sent to Europe, to study and subsequently report upon the true condition of the beet sugar industry.

A correspondent writes from Farnham, Canada, that the Canadian government grants a bounty of 2 cents per pound on beet sugar during campaign 1891-92. Duties on raw sugar were abolished last June.

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AMERICAN WORKSHOPS.

An interesting paper on some of the leading American workshops was lately read before the members of the Manchester Association of Engineers on Saturday by Mr. Hans Renold. After expressing his opinion that the English people did not sufficiently look about them or try to understand what other nations were doing, Mr. Renold stated that he had visited that portion of America known as New England, and the works he had inspected were among the best in the United States. Among the many special features he had noticed he mentioned that in a Boston establishment where milling machine cutters were made he had found that L1 spent in wages produced as much as L30 to L40 worth of goods, the cutters being made at the rate of about sixty-four per hour by about a dozen men. Another noticeable feature was the exceptional care taken in storing tools in American workshops. These, in fact, were treated as if they were worth their weight in gold; they were stored in safes much in the same manner as we in England stored our money. He was, however, impressed by the fact that the mere understanding of the method of American working would not enable them to do likewise in England, because the American workmen had gone through a special training, and a similar training would be necessary to enable English workmen to adapt themselves to American machines. One very noticeable feature in American engineering shops which he visited was that all the machine men and turners were seated on blocks or stools at their machines, and the question naturally arose in his mind what would English engineers say if such a practice were adopted in their shops. In other ways he was also struck by the special attention devoted to the comfort of the workmen, and he was much impressed by the healthy condition of the emery polishing shops as compared with similar shops in this country. In England these shops in most cases were simply deathtraps to the workmen, and he urged that the superior method of ventilation carried out in the States should be adopted in this country by introducing a fan to each wheel to take away the particles, etc., which were so injurious. One very special feature in the United States was that works were devoted to the manufacture of one particular article to an almost inconceivable extent, and that heavy machine tools complete and ready to be dispatched were kept in stock in large numbers. American enterprise was not hampered as it too frequently was in England by want of capital; while in England we were ready to put our savings in South American railways or fictitious gold mines, but very chary about investing capital which would assist an engineer in bringing out an honest improvement, in America, on the other hand, it was a common practice among the best firms to invest their savings over and over again in their works, which were thus kept in a high state of perfection.

The above paper came in for some pretty severe criticism. Mr. John Craven remarked that although Mr. Renold had gone over a wide field of subjects, he had practically confined his remarks to Messrs. Brown & Sharpe's establishment, and while he (Mr. Craven) was ready to admit that so far as high class work and sanitary arrangements were concerned, Messrs. Brown & Sharpe's were a model, they could not be put forward as representative of American establishments generally. As a matter of fact, many of the American workshops were not as good as a large number of similar workshops in Manchester. Mr. Renold had referred to the extensive use of gear cutters in the United States, but he might point out that it was in Manchester that the milling machine was first made. Mr. Samuel Dixon said he had certainly come to the conclusion that no better work was done in America than could be and was being done in this country; while as regards the enormous production of milling cutters, that was simply an example of what could be done where large firms devoted themselves to the production of one specialty. With regard to the statement made by Mr. Renold that the American thread was preferable to the Whitworth thread, he might say he entirely disagreed with such a conclusion, and he might add that after visiting a variety of Continental and American workshops he should certainly not, if he were called upon to award the palm of superiority in workmanship, go across the Atlantic for that purpose. Mr. J. Nasmith remarked that whether English engineers were the inventors of the milling machine or not, it must be admitted that it was through this type of cutter being taken up by the Americans that milling had become the success it was at the present time. English engineers were very conservative, and it was only through the pressure of circumstances that milling machines came into general use in this country. When American inventions were brought to England they were generally improved to the highest degree, but he thought the chief fault of both American and Continental engineers was what one might call "over-refinement;" there was such a thing as over-finishing an object and overdoing it. If, however, American machinery was so much superior to what we had in this country, as asserted by the reader of the paper, how was it that cotton machinery, with all its intricacies, could be sent to the United States, in the face of American manufacturers, even though the cost was increased from 40 to 60 per cent.? At the present time it was possible for English machinists to secure contracts for the whole of the machinery in an American mill, and inclusive of freight charges and high tariff, deliver and erect it in America at a lower cost than American engineers with all the advantages of their immeasurably superior tools were able to do. Another speaker, Mr. Barstow, ridiculed the idea that the Americans could be so pre-eminent in the manufacture of emery wheels as might be inferred from Mr. Renold, when they had before them the fact that from the neighborhood of Manchester thousands of emery wheels were every year exported to the United States.

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MODERN METHODS OF QUARRYING.

Mr. Wm. L. Saunders, for many years the engineer of the Ingersoll Rock Drill Co., and hence thoroughly familiar with modern quarrying practice, read a paper before the last meeting of the American Society of Civil Engineers on the above subject, containing many interesting points, given in the _Engineering News_, from which we abstract as follows.

As a preliminary to describing the new Knox system of quarrying, which even yet is not universally known among quarrymen, Mr. Saunders gives the following in regard to older methods:

The Knox system is a recent invention; no mention was made of
it in the tenth census, and no description has yet been given
of it in any publications on quarrying. The first work done by
this method was in 1885, and at the close of that year 2
quarries had adopted it. In 1886 it was used in 20 quarries;
in 1887 in 44, in 1888 in upward of 100, and at the present
time about 300 quarries have adopted it. Its purpose is to
release dimension stone from its place in the bed, by so
directing an explosive force that it is made to cleave the
rock in a prescribed line without injury. The system is also
used for breaking up detached blocks of stone into smaller
sizes.

Quarrymen have, ever since the introduction of blasting, tried to direct the blast so as to save stock. Holes drilled by hand are seldom round. The shape of the bit and their regular rotation while drilling usually produce a hole of somewhat triangular section. It was observed, many years ago, that when a blast was fired in a hand-drilled hole the rock usually broke in three directions, radiating from the points of the triangle in the hole. This led quarrymen to look for a means by which the hole might be shaped in accordance with a prescribed direction of cleavage.

The oldest sandstone quarries in America are those at Portland, Conn. It was from these quarries that great quantities of brownstone were shipped for buildings in New York. The typical "brownstone front" is all built of Portland stone. As the Portland quarries were carried to great depths the thickness of bed increased, as it usually does in quarries. With beds from 10 to 20 ft. deep, all of solid and valuable brownstone, it became a matter of importance that some device should be applied which would shear the stone from its bed without loss of stock and without the necessity of making artificial beds at short distances. A system was adopted and used successfully for a number of years which comprised the drilling of deep holes from 10 to 12 in. in diameter, and charging them with explosives placed in a canister of peculiar shape. The drilling of this hole is so interesting as to warrant a passing notice. The system was similar to that followed with the old fashioned drop drill. The weight of the bit was the force which struck the blow, and this bit was simply raised or lowered by a crank turned by two men at the wheel. The bit resembled a broad ax in shape, in that it was extremely broad, tapering to a sharp point, and convex along the edge.

Fig. 1 illustrates in section one of the Portland drills, and a drill hole with the canister containing the explosive in place. The canister was made of two curved pieces of sheet tin with soldered edges, cloth or paper being used at the ends. It was surrounded with sand or earth, so that the effect of the blast was practically the same as though the hole were drilled in the shape of the canister. In other words, the old Portland system was to drill a large, round hole, put in a canister, and then fill up a good part of the hole. Were it possible to drill the hole in the shape of the canister, it would obviously save a good deal of work which had to be undone. The Portland system was, therefore, an extravagant one, but the results accomplished were such as to fully warrant its use. Straight and true breaks were made, following the line of the longer axis of the canister section, as in Fig. 2.

It was found that with the old Portland canister two breaks might be made at right angles by a single blast, when using a canister shaped like a square prism. In some of the larger blasts, where blocks weighing in the neighborhood of 2,000 tons were sheared on the bed, two holes as deep as 20 ft. were drilled close together. The core between the holes was then clipped out and large canisters measuring 2 ft. across from edge to edge were used.

In regard to another of the older systems of blasting, known as Lewising, Mr. Saunders says:

A Lewis hole is made by drilling two or three holes close
together and parallel with each other, the partitions between
the holes being broken down by using what is known as a
broach. Thus a wide hole or groove is formed in which powder
is inserted, either by ramming it directly in the hole, or by
puling it in a canister, shaped somewhat like the Lewis hole
trench. A complex Lewis hole is the combination of 3 drill
holes, while a compound Lewis hole contains 4 holes. Lewising
is confined almost entirely to granite. In some cases a series
of Lewis holes is put in along the bench at distances of 10
and 25 ft. apart, or even greater, each Lewis hole being
situated equidistant from the face of the bench. The holes are
blasted simultaneously by the electric battery.

After noting another system used to a limited extent, and not to be commended, viz., the use of inverted plugs and feathers (the plugs and feathers being inserted as a sort of tamping which the blast drives upward to split the rock), Mr. Saunders continues in substance as follows:

It is thus seen that the "state of the art" has been
progressive, though it was imperfect. Mr. Sperr, in his
reference to this subject, made in the report of the tenth
census, says: "The influence of the shape of the drill hole
upon the effects of the blast does not seem to be generally
known, and a great waste of material necessarily follows."
This was written but a few years before the introduction of
the new system, and it is doubtless true that attention was
thus widely directed to the conspicuous waste, due to a lack
of knowledge of the influence of the shape of a drill hole on
the effect of a blast. The system developed by Mr. Knox
practically does all and more than was done by the old
Portland system, and it does it at far less expense. It can
best be described by illustrations.

Fig. 3 is a round hole drilled either by hand or otherwise, preferably otherwise, because an important point is to get it round. Fig. 4 is the improved form of hole, and this is made by inserting a reamer, Figs. 5 and 6, into the hole in the line of the proposed fracture, thus cutting two V-shaped grooves into the walls of the hole. The blacksmith tools for dressing the reamers are shown in Fig. 7. The usual method of charging and tamping a hole in using the new system is shown in Fig. 8. The charge of powder is shown at C, the air space at B and the tamping at A. Fig. 9 is a special hole for use in thin beds of rock. The charge of powder is shown at C, the rod to sustain tamping at D, air space at BB, and tamping at A.

Let us assume that we have a bluestone quarry, in which we may illustrate the simplest application of the new system. The sheet of stone which we wish to shear from place has a bed running horizontally at a depth of say 10 ft. One face is in front and a natural seam divides the bed at each end at the walls of the quarry. We now have a block of stone, say 50 ft. long, with all its faces free except one--that opposite and corresponding with the bench. One or more of the specially formed holes are put in at such depth and distance from each other and from the bench as may be regulated by the thickness, strength and character of the rock. No man is so good a judge of this as the quarry foreman who has used and studied the effect of this system in his quarry. Great care should be taken to drill the holes round and in a straight line. In sandstone of medium hardness these holes may be situated 10, 12 or 15 ft. apart. If the bed is a tight one the hole should be run entirely through the sheet and to the bed; but with an open free bed holes of less depth will suffice.

The reamer should now be used and driven by hand. Several devices have been applied to rock drills for reaming the hole by machinery while drilling; that is, efforts have been made to combine the drill and the reamer. Such efforts have met with only partial success. The perfect alignment of the reamer is so important that where power is used this point is apt to be neglected. It is also a well known fact that the process of reaming by hand is not a difficult or a slow one. The drilling of the hole requires the greatest amount of work. After this has been done it is a simple matter to cut the V-shaped grooves. The reamer should be applied at the center, that is, the grooves should be cut on the axis or full diameter of the hole. The gauge of the reamer should be at least 11/2 diameters. Great care should be taken that the reamer does not twist, as the break may be thereby deflected; and the reaming must be done also to the full depth of the hole.

The hole is now ready for charging. The powder should be a low explosive, like black or Judson powder or other explosives which act slowly. No definite rule can be laid down as to the amount of powder to be used, but it should be as small as possible. Very little powder is required in most rocks. Hard and fine grained stone requires less powder than soft stone. Mr. Knox tells of a case which came under his observation, where a block of granite "more than 400 tons weight, split clear in two with 13 oz. of FF powder." He compares this with a block of sandstone of less than 100 tons weight "barely started with 21/2 lb. of the same grade of powder, and requiring a second shot to remove it."

It is obvious that enough powder must be inserted in the hole to produce a force sufficient to move the entire mass of rock on its bed. In some kinds of stone, notably sandstone, the material is so soft that it will break when acted upon by the force necessary to shear the block. In cases of this kind a number of holes should be drilled and fired simultaneously by the electric battery. In such work it is usual to put in the holes only 4 or 5 ft. apart. The powder must, of course, be provided with a fuse or preferably a fulminating cap. It is well to insert the cap at or near the bottom of the cartridge, as shown in Figs. 8 and 9.

After the charge the usual thing to do is to insert tamping. In the improved form of hole the tamping should not he put directly upon the powder, but an air space should be left, as shown at B, Fig. 8. The best way to tamp, leaving an air space, is first to insert a wad, which may be of oakum, hay, grass, paper or other similar material. The tamping should be placed from 6 to 12 in. below the mouth of the hole. In some kinds of stone a less distance will suffice, and as much air space as practicable should intervene between the explosive and the tamping. If several holes are used on a line they should be connected in series and blasted by electricity. The effect of the blast is to make a vertical seam connecting the holes, and the entire mass of rock is sheared several inches or more.

The philosophy of this new method of blasting is simple, though a matter of some dispute. The following explanation has been given. See Fig. 10.

"The two surfaces, _a_ and _b_, being of equal area, must receive an equal amount of the force generated by the conversion of the explosive into gas. These surfaces being smooth and presenting no angle between the points, A and B, they furnish no starting point for a fracture, but at these points the lines meet at a sharp angle including between them a wedge-shaped space. The gas acting equally in all directions from the center is forced into the two opposite wedge-shaped spaces, and the impact being instantaneous the effect is precisely similar to that of two solid wedges driven from the center by a force equally prompt and energetic. All rocks possess the property of elasticity in a greater or less degree, and this principle being excited to the point of rupture at the points, A and B, the gas enters the crack and the rock is split in a straight line simply because under the circumstances it cannot split in any other way."

Another theory which is much the same in substance is then given, and after some general discussion of the theory of the action of the forces under the several systems, the paper continues:

The new form of hole is, therefore, almost identical in principle with the old Portland canister, except that it has the greater advantage of the V-shaped groove in the rock, which serves as a starting point for the break. It is also more economical than the Portland canister, in that it requires less drilling and the waste of stone is less. It is, therefore, not only more economical than any other system of blasting, but it is more certain, and in this respect it is vastly superior to any other blasting system, because stone is valuable, and anything which adds to the certainty of the break also adds to the profit of the quarryman.

It is doubtless true that, notwithstanding the greater area of pressure in the new form of hole, the break would not invariably follow the prescribed line but for the V-shaped groove which virtually starts it. A bolt, when strained, will break in the thread whether this be the smallest section or not, because the thread is the starting point for the break. A rod of glass is broken with a slight jar provided a groove has been filed in its surface. Numerous other instances might be cited to prove the value of the groove. Elasticity in rock is a pronounced feature, which varies to a greater or less extent; but it is always more or less present. A sandstone has recently been found which possesses the property of elasticity to such an extent that it may be bent like a thin piece of steel. When a blast is made in the new form of hole the stone is under high tension, and being elastic it will naturally pull apart on such lines of weakness as grooves, especially when they are made, as is usually the case in this system, in a direction at right angles with the lines of least resistance.

Horizontal holes are frequently put in and artificial beds made by "lofting." In such cases where the rock has a "rift" parallel with the bed, one hole about half way through is sufficient for a block about 15 ft. square, but in "liver" rock the holes must be drilled nearly through the block and the size of the block first reduced.

A more difficult application of the system, and one requiring greater care in its successful use, is where the block of stone is so situated that both ends are not free, one of them being solidly fixed in the quarry wall. A simple illustration of a case of this kind is a stone step on a stairway which leads up and along a wall, Fig. 11. Each step has one end fixed to the wall and the other free. Each step is also free on top, on the bottom and on the face, but fixed at the back. We now put one of the new form of holes in the corner at the junction of the step and the wall. The shape of the hole is as shown in Fig. 12.

It is here seen that the grooves are at right angles with each other, and the block of stone is sheared by a break made opposite and parallel with the bench, as in the previous case, and an additional break made at right angles with the bench and at the fixed end of the block. Sometimes a corner break is made by putting in two of the regular V-shaped holes in the lines of the proposed break and without the use of the corner hole. A useful application of this system is in splitting up large masses of loose stone. For this purpose the V-shaped grooves are sometimes cut in four positions and breaks are made in four directions radiating from the center of the hole as shown in Fig. 12. In this way a block is divided into four rectangular pieces.

Though the new system is especially adapted to the removal of heavy masses of rock, yet it has been applied with success in cases where several light beds overlie each other. In one such instance 10 sheets, measuring in all only 6 ft., were broken by a blast, but in cases of this kind the plug and feather process applies very well, and the new system, when used, must be in the hands of an expert, or the loss will be serious.