Chapter XII: TECHNOLOGY.--The Tanning Materials of Europe.--The natural (4)

It was while at Glasgow University, working under such influences and in such an atmosphere of intellectual activity, that the accident of the Newcomen model engine needing repair brought to the mind of Watt the opportunity which, availed of at once, made him famous and gave the world its greatest aid, its most powerful servant. The observing mind of the great mechanic immediately noted its defects, sought their causes, found their remedy. He discovered, at once, that the quantity of steam entering the cylinder of the little engine has four times the volume of the cylinder receiving it: in other words, three-fourths of that steam must be condensed immediately on entrance. This meant, evidently, that only one-fourth of the steam supplied was utilized, and even then inefficiently, in doing its work. The reason of this was as easily seen, immediately the fact was revealed. As Watt himself expressed it, the causes of this loss, causes which would obviously be exaggerated in a small engine, were: "First, the dissipation of heat by the cylinder itself, which was of brass and both a good conductor and a good radiator. Secondly, the loss of heat consequent upon the necessity of cooling down the cylinder at every stroke in producing the vacuum. Thirdly, the loss of power due to the pressure of vapor beneath the piston, which was a consequence of the imperfect method of condensation." This much determined, the next step looked toward the confirmation of his conclusions and the remedy of the defects.

To meet the first difficulty he made a cylinder of wood, soaked in oil and baked, a non-conducting and non-radiating material. Then he was able to determine with some accuracy the quantities of steam and injection water used in the engine; and a comparison with the original cylinder and its operation showed that not only four times the quantity of steam, but also four times the amount of injection water was used as was necessary, assuming wastes checked. Further scientific research on the part of Watt gave him measures of specific heats of the metals and of wood, the specific volumes of steam at various working pressures, the evaporative efficiency of boilers, the pressures and temperatures of steam in the boiler under specified conditions, the quantities of steam and of water required for the operation of his little condensing engine.

Then came his enunciation of the grand principle of economy in the construction and operation of the steam engine: "Keep the cylinder as hot as the steam which enters it," as he expressed it. This was Watt's guiding principle, as it has been that of all his successors in the improvement of the economic performance of the steam engine and of all other heat engines. The great source of waste is the dispersion of heat, uselessly, which should be applied to the production of work by its transformation, thermodynamically, into the latter form of energy. The second form of waste is that of power thus produced in the unprofitable work of moving the parts of the engine itself; and the third is that of heat by transfer, without transformation, by conduction and radiation to surrounding bodies. In modern engines, the latter is but three or five per cent., in the best cases; the second waste constitutes perhaps ten per cent.; while the first of these losses amounts very usually to seventy per cent., of which last one-third or one-fourth is of the kind discovered by Watt, the rest being the thermodynamic waste incident to all known methods of operation of heat engines, and apparently unavoidable. In our very best and largest engines, the waste found by Watt to constitute three fourths of all heat supplied has been brought down to ten per cent., a fact which well exemplifies the advances made since his time of apprenticeship by himself and his successors of this nineteenth century. The steam engine of to-day, in its most successful operation, gives us twenty-five times as much power from a pound of coal as did the engine that the great inventor sought to improve: this is the magnificent fruit of that one discovery of James Watt, and of application of the simple principle which he so concisely and clearly stated.

The method adopted by Watt to secure a remedy, so far as practicable, of this defect of the older machine was as simple and as perfect as was the principle which it embodied. He first removed from the cylinder the prime source of its wastes; providing a separate condenser, and thus avoiding the repeated chilling of its surfaces by the cold water used in condensing the steam at exhaust, and also permitting its strokes to be made with far greater frequency, thus giving less time for cooling by the influence of the remaining vapors after condensation. He next went still further, and provided the cylinder with a closed top, keeping out the air, and a "jacket" of hot boiler steam to _keep_ it as hot as the steam which entered it. These were the two great improvements which converted the first real steam engine into an economical form of heat engine and essentially finished the work so grandly begun by Newcomen and Calley. These changes gave us the modern steam engine; and these are Watt's first and greatest, but by no means only, contributions to the production of the modern world with all its comforts, its luxuries and its opportunities for material, intellectual and moral advancement of individual and of race. His work was to this extent complete in 1765.

But Watt did not stop here. There still remained for him the no less important and the, in some senses, still more imposing, work of finding employment for the new servant of mankind and of setting it at its work of giving the human arm a thousand times greater strength, to the mind of man uncounted opportunities to promote the advancement of knowledge, of civilization, of every good of the race. His was still the task of adapting the new machine to all the purposes of modern industry. It had been hitherto confined to the task of raising water from the depths of the mine; it was now to be harnessed to the railway train; to be made to drive the machinery of the mill, to apply its marvelous power to the impulsion of the river boat and ocean steamer; to furnish energy, through endless systems of transfer and use, to every kind of work that man could devise and should invent. All this meant the giving of the machine forms as various as the purposes to which it was to be devoted. It had previously only raised and depressed a rod; it must now turn a shaft. It had then only operated a pump; it must now turn a mill, grind our grain, spin our threads, weave our cloths, drive our shops and factories, supply the powerful blast of the iron furnace. It must be made to move with the utmost conceivable regularity, and must, with all this, do its work in the development of the hidden energy of the fuel, with the greatest possible economy, through the expansion of its steam. All this was achieved by James Watt.

The invention of the double-acting engine, in which the impulsion of the steam is felt both in driving the piston forward and in forcing it backward, both upward and downward, the application of its force through crank and fly wheel, the creation of an automatic system of governing its speed, and the discovery of the economy due to its complete expansion, were all improvements of the first magnitude, and of the greatest practical importance; and all these were in rapid succession brought into existence by the creative mind that had apparently been brought into the world for the express purpose of giving to the hand of man this mighty agent, to perfect the mightiest power that mind of man has yet conceived.

But to do the rest required more than inventive genius and mechanical skill. It demanded capital and the stored energy of labor and genius in other fields, directed by the mind of a great "captain of industry." This came to Watt through Matthew Boulton, a manufacturer of Birmingham, whose father and ancestors had gradually and toilsomely, as always, accumulated the property needed for the prosecution of a great business. The combination of genius and capital is always an essential to success in such cases; and good fortune, a Providence, we may well say, brought together the genius and the capitalist to do their work, hand in hand, of providing the world with the steam engine. Hand in hand they worked, and all the world to-day, and the race throughout its future life, must testify gratitude for the inexpressible obligations under which these two men have placed them, doing the work of the world.

Boulton & Watt, the capitalist with the inventor, gave the world the steam engine, finally, in such form and in such numbers that its permanent establishment as the servant of man was insured. The capitalist was as essential an element of success as was the inventor, and, in this instance, as in a thousand others, the race is indebted to that much-abused friend of the race, the capitalist, for much that it enjoys of all that it desires. The industry and patience, the skill and the wisdom required for the accumulation of this energy stored for future use in great enterprises is as important, as essential, as inventive power or any other form of genius. Talent and genius must always aid each other. This firm was established in 1764 and its main resources, aside from the bank account, were Watt's patent, about expiring, and Watt's genius, and Boulton's talent as a man of business. The patent was extended for twenty-four years, the new inventions of Watt, now beginning to pour from his prolific brain in a wonderful stream, were also patented, and the whole works were soon employed upon the construction of engines for which numerous orders soon began to pour in upon the now prosperous builders. The patent law established Boulton and Watt and the firm paid back the nation with handsome usury, giving it unimaginable profits indirectly through its control of the work of the world and large profits directly through the business brought them from all parts of the then civilized globe. There has never, in the history of the world, been a more impressive illustration of the value to a nation of that generous public policy, that simply just legislation, which gives to the man of brain control of the products of his mind. For a hundred years, Great Britain has, largely through her encouragement of the inventor and her protection of his mental property by securing the fruits of his labors, in fair portion, to him, gained the power of dictating to the world and has gained an advance that cannot be measured. Watt and Arkwright and Stephenson and Crompton and their ilk, protected by their government and its patent laws, made their country the peaceful conqueror of the world. The story of the work of the inventor is a poem of mighty meaning and of wonderful deeds. The inventor proved himself a mightier magician than ever the world had seen.

"A creature he called to wait on his will,
Half iron, half vapor--a dread to behold;
Which evermore panted, and evermore rolled,
And uttered his words a millionfold."

Such was the outcome of this grand modern "trust," a combination of the wisest legislation, the most brilliant invention, and the most wisely applied capital. There are "trusts" of which the outcome is most beneficent.

Since the days of Watt, the improvement of the steam engine and the work of inventors has been confined to matters of detail. All the fundamental principles were developed by Watt and his predecessors and contemporaries and it only was left to his successors to find the best ways of carrying them into effect. But these matters of detail have been found to involve opportunities to make enormous strides in the direction of securing improved efficiency of the machine. The further application of the principle which led Watt to his greatest inventions; of the principle, keep the cylinder as hot as the steam which enters it, of that which he enunciated relative to the advantage of expanding steam, and of that affecting the regulation of the machine; have reduced the costs of steam and of fuel to a small fraction of their earlier magnitude. One ton of engine to-day does the work of eight or ten in the time of Watt: one pound of fuel or of steam gives to-day ten times the power then obtained from it. A steamship now crosses the Atlantic in one-eighth the time required by the famous "liner" of the "Black Ball Line." The wastes of the engine have been brought down from above eighty per cent. to eight; and a half-ounce of fuel on board ship will now transport a ton of cargo over a mile of ocean.

FREDERICK E. SICKELS gave us the first practicable form of expansion gear in 1841; GEORGE H. CORLISS gave a new type of engine of marvelous perfection and economy in 1849; Noble T. Green, Wm. Wright and many less well known but no less meritorious inventors have since done their part in the transformation of the old engine of Watt into the modern wonder of concentrated and economical power, and marvel of accurate and beautiful design and workmanship. The "trip cut-off," with reduced clearances, increased boiler pressure, higher rates of expansion, accelerated speeds of engine, better construction in all respects, as well as improved design, have enabled us to avail ourselves to the utmost of the principles of Watt, and our mills, our railways, our steamers and our fields, even, have gained almost as extraordinarily by these advances, since the days of the great inventor, as through his immediate labors.

With the introduction of the new form of older energy, electricity, with the reduction of the lightning into thraldom, has now come a new impulse affecting all the industries. Through its mysterious, its still unknown action, steam now reaches out far from its own place, driving the electric car along miles of rail; giving light throughout all the country about it, turning night into day, and repressing crime while encouraging legitimate labor, reaching into distant chambers and every little workshop, to offer its powerful aid in all the distributed work of cities. Without the steam engine there would be little work available for electricity, but the appearance of this, the latest and most useful handmaid of steam, has given the engine work to do in an uncounted number of new fields, has called in the inventor once more to adapt steam to its new work. The "high-speed engine" is the latest form of the universal helper. And such has been the readiness and the intelligence of the contemporary inventor that we now have engines capable of turning their shafts three hundred rotations a minute and without a perceptible variation of velocity, whatever the change of load or the suddenness with which it is varied. In the days of Watt a fluctuation of five per cent. in speed was thought wonderfully small; in those of Corliss, the variation was restricted to two per cent. and we wondered at this unanticipated success. To-day, thanks to Porter and Allen, to Hartnell, to Hoadley, to Sims, to Thomson, to Sweet, to Ide, and to Ball, we have seen the speed fluctuation restricted to even less than one per cent. of its normal average.

The inventors of the steam engine are, through their representatives of to-day, according to the statisticians, doing the equivalent of twelve times the work of a horse, for every man, woman and child on the globe. We have not less, probably, than a half million of miles of railway, transporting something over 150,000,000,000 of tons a mile a year. A horse is reckoned to haul a ton weight about six and a half miles, day by day, by the year together. In the United States, it is reckoned that the steam engine, on the railways alone, hauls a thousand tons one mile, for every inhabitant of the country, every year, or, if it is preferred to so state it, a ton a thousand miles. This is the way in which the East and the West are, by the inventors of the steam engine, enabled to help each other. This costs about $10 each individual; it would require some 25 millions of horses to do the work, and would cost about $1,000 a family, which is more than twice the average family earnings.

Dr. Strong, in that remarkable book, "Our Country," says: "One man, by the aid of steam, is able to do the work which required two hundred and fifty men at the beginning of the century. The machinery of Massachusetts alone represents the labor of more than 100,000,000 men, as if one-half of all the workmen of the globe had engaged in her service." And again: "Some thirty years ago, the power of machinery in the mills of Great Britain was estimated to be equal to 600,000,000 men, or more than all the adults, male and female, of all mankind." Mr. Gladstone estimated that the aggregation of wealth on the globe during the whole period from the birth of Christ to that of Watt was equaled by the production in twenty years, at the middle of this century, with the aid of machinery driven by the fruit of the brain of the inventors of the steam engine. We may probably now safely estimate the former quantity as rivaled in less than five years, while, since the birth of Watt and his engine, and the production of the spinning mule, the power loom, the cotton gin and our own patent system and its marvelous mechanism, all events of a century ago, we may estimate that they have, together, accomplished more in this period which we now celebrate than could have been done in a millenium of milleniums without these now subjected genii. But the power behind all these curious inventions and their work is that of steam. The steam engine even supplies power to the telegraph and transports words and thought as well as cotton bales and coal.

And now what has this combination of legislation for private protection and public good, of a genius producing great inventions, and of the accumulated capital of earlier years, brought about?

It has given us the best fruits of science in permanent possession. The study of science invariably aids, in a thousand ways, the progress of mankind. It gives us new conceptions of nature and of the possibilities of art; it promotes right ways of work and of study; it teaches the inventor and the discoverer how most surely and promptly to gain their several ends, it gives the world the results of all acquired knowledge in concrete form. This one instance which we are now especially interested in contemplating has performed more wonderful miracles than ever Aladdin's genii attempted. One man, with a steam engine at his hand, turns the wheels of a great mill, drives forty thousand spindles, applies a thousand horse power to daily work in the spinning of threads, the weaving of cloth, the impulsion of a steamboat, or the drawing of great masses of hot iron into finest wire. This puny creature, his mind in his finger tips, exerts the power of ten thousand men, working with muscle alone, and, aided by a handful of women, boys and girls, clothes a city. A half dozen men in the engine room of an ocean steamer, with a hundred strong laborers in the boiler room and on deck, transports colonies and makes new nations, brings separated peoples together, unites countries on opposite sides of the globe, brings about easy exchanges between pole and equator. One man on the footboard of the locomotive, one man shoveling into the furnaces the black powder that incloses the energy stored in early geological ages, a half dozen men mounted on the long train of following vehicles, combine to bring to the mill girl in Massachusetts, the miner in Pennsylvania, the sewing woman, and the wealthy merchant, her neighbor in New York, the flour made in Minnesota from the grain harvested a few weeks earlier in Dakota. All the world is served faithfully and efficiently by this unimaginable power, this product of the brain of the inventor, protected by the law, stimulated and aided by the capital that it has itself almost alone produced.

And thus have the inventors of the steam engine set in motion and placed at the disposal of mankind for every form of useful work all the great forces of nature; thus Hero of Alexandria touched the then concealed spring which called all the genii of earth, fire, water and air to do the bidding of the race. Thus Papin, Worcester, Newcomen, Watt, and Corliss and others of our own contemporaries, have applied the genii to their task of leveling mountains, traversing seas, continents, and the depths of the earth, building ships, locomotives, hamlets and cities, cottages and palaces, turning the spindle, operating the loom, and setting motion and giving energy to every machine, doing the work of thousands of millions of men, converting barbarism into civilization, giving necessaries of life in profusion, comforts in plenty, and luxuries in superabundance.

Aiding and working hand in hand with those other genii of progress, the inventors of the printing press and of the telegraph, the telephone, and the electric railway, of the modern system of textile manufactures, of iron and steel making, of the mowing machine and the harvester, they have compressed into two centuries the progress of a millennium, destitute of their aid. Every step taken under their stimulus, and with their help, is a step toward a higher life for all, intellectually and morally as well as physically; every advance in the improvement of their work is a gain to every man, woman, and child; every improvement of the steam engine is a help to the whole world. This progress makes the day of the extinction of the system now grinding the populations of the earth into the ground, the day of the abolition of armies and the restoration to the people of that freedom which characterized the times of the patriarchs, and of the restoration of the rights of the citizen to his own time and strength and producing power, perceptibly nearer.

When this final revolution shall have been accomplished, and when all the world has settled down to the steady and undisturbed work of production by daily and regular labor, aided by the genii of steam, of electricity, of all nature, combined for good, the results of the intellectual activity of the inventors of the steam engine will be fully seen. Then no monument will be required to keep green the memory of Watt, Corliss, or any other of these great men, but it will be said of them, as of Sir Christopher Wren in the epitaph in St. Paul's: "Seek you a monument, look about you!" Every wreath of steam rising to the heavens from factory, mill or workshop will be a reminder of Hero of Alexandria, every mine will possess a memorial to Papin, Worcester and Savery; every steamship will bring into grateful memory Fitch and Stevens, and Bell and Fulton; thousands of locomotives, crossing the continents, will perpetuate the thought of the Stephensons and their colleagues in the introduction of the railway; the hum of millions of spindles and the music of the electric wire will tell of the work of Corliss and his contemporaries and successors who made these things possible, and all kingdoms and races, all nations, will revere the name of James Watt, the genius to whom the world is most indebted for the beginnings of all this later and grander civilization which has converted the slow progress of earlier centuries into the meteor-like advance of to-day toward a future as grand and as mighty and as noble as humanity shall choose to make it.

* * * * *

IMPROVED HAND CAR.

In the accompanying illustration we show a new design of hand car, being introduced by the Courtright Manufacturing Co., of Detroit. It will be seen that the apparatus for propelling the car is very different from the mechanism generally used. An upright framework secured to the platform carries a large sprocket wheel, which is connected to a smaller one upon one of the axles by means of a chain. The larger sprocket wheel is rotated by means of a triangular shaped lever attached at the lower corner to the crank of the sprocket wheel and having a handle at each of its upper corners. It is hinged upon a fulcrum which slides upon the two vertical rods shown in the illustration. It will be seen that this gives a peculiar movement to the handles by which the operators propel the car, but it has been found that the motion is an excellent one, and it is claimed that a higher speed can be obtained with the mechanism here shown than with any other now in use. There is practically no dead center, as in the case where the ordinary crank and lever is used. A number of leading roads have given the car a trial, and being well satisfied it, have given orders for more. The company claim that a car with 20 in. wheels can easily be made to attain a speed of 15 miles an hour by two men.--_Railway Review_.

* * * * *

THE CONIC SECTIONS.

By Prof. C.W. MACCORD, Sc.D.

In Fig. 1 let D be a given point, and O the center of a given circle, whose diameter is FG. Bisect DF at A. Also about D describe an arc with any radius DP greater than DA, and about O another arc with a radius OP = DP + FO, intersecting the first arc at P, then draw PD, and also PO, cutting the circumference of the given circle in L. Since PD = PL, and DA = AF, it is evident that by repeating this process we shall construct a curve PAR, which satisfies the condition that _every point in it is equally distant from a given point and from the circumference of a given circle_. Since PO-PD = LO, and AO-AD = FO, this curve is one branch of the hyperbola of which D and O are the foci.

Bisect DG at B, then about D describe an arc with any radius DQ greater than DB, and about O another are with radius OQ = DQ-FO; draw from Q the intersections of these arcs, the line QD, and also QO, producing the latter to cut the circumference in E. By this process we may construct the curve QBZ, each point of which is also equally distant from the given point D, and from the concave instead of the convex arc of the given circumference. The difference between QD and QO being constant and equal to FO, and AB being also equal to FO, this curve is the other branch of the same hyperbola, whose major axis is equal to the radius of the given circle.

The tangent at P bisects the angle DPL, and is perpendicular to DL, which it bisects at a point I on the circumference of the circle whose diameter is AB, the major axis, the center being C, the middle point of D O. As P recedes from A, it is evident that the angles P D L, P L D, will increase, until D L assumes the position D T tangent to the given circle, when they will become right angles. P will therefore be infinitely remote, and the point I having then reached t, where D T touches the smaller circle, C t S will be an asymptote to the curve. This shows that the measurements from the convex arc, for the construction of A P, are made only from the portion F T of the given circumference.

In the diagram the point Q is so chosen that D L produced passes through E, so that Q J, the tangent at Q, is parallel to P I. It will thus be seen that the measurements from the concave arc, for the construction of B Q, are confined to the portion G T of the given circumference. As D L E rises, the points P and Q recede from A and B, the points L and E approach each other, finally coinciding at T; at this instant I and J fall together at t, so that S S is the common asymptote to A P and B Q.

In Fig. 2 the given point D lies within the circumference of the given circle. Bisect D F at A, and D G at B; about D describe an arc with any radius D P greater than D A, and about O another, with radius O P = O F--D P, these arcs intersect in P, and producing O P to cut the circumference in L, we have P D = P L. Similarly E D = E H, U D = U W, etc. And since P D + P O = L P + P O, D E + E O = H E + E O, and so on, the curve is obviously the ellipse of which the foci are D and O, and the major axis is A B = F O, the radius of the given circle.

If, as in Fig. 3, the given point be made to coincide with the center of the circle, the ellipse becomes a circle with diameter A B = F O. But if the point be placed upon the circumference, as in Fig. 4, the ellipse will reduce to the right line A B coinciding with F O.

In this case we may also apply the same process as in Fig. 1; D T becomes a tangent at D to the circumference, and the asymptotes coincide with the axis of the hyperbola, of which one branch reduces to the right line A P extending from A to infinity on the left, and the other reduces to the right line B G Q, extending from B to infinity on the right.

If the circle be reduced to a point, as in Fig. 5, the resulting locus is a right line perpendicular to and bisecting D O. If on the other hand the diameter of the given circle be infinite, the circumference, as in Fig. 6, becomes a right line perpendicular to the axis at F, and the curve satisfies the familiar definition of the parabola, D E being equal to E H, D P equal to P L, and so on.

In Fig. 7, as in Fig. 1, DT is tangent at T to the given circle whose center is O, and at t to the circle about C whose diameter is AB, the major axis. Since DTO is a right angle, T lies upon the circumference of the circle whose center is C, and diameter DO; this circle cuts the asymptote SCS at M and N. The semi-conjugate axis is a mean proportional between D A and AO; now drawing TM and TN, it is seen that Tt is that mean proportional; and a circle described about C with that radius will be tangent to TO. DT, then, is the radius of the circle to be described about the focus of the conjugate hyperbola for its construction according to the enunciation first given: and we observe that DT and TO are supplementary chords in the circle about C through D and O. The conjugate foci must therefore lie upon this circumference, at D' and O'; and since D'O' is perpendicular to DO, D'T will be perpendicular and T'O' will be parallel to SCS.

Now as TO increases, T'O' will diminish, until, when TO equals DO, T'O' will vanish and with it Ct'; and at this crisis, the case is the same as in Fig. 4; but the conjugate hyperbola logically reduces to _two_ right lines, extending from C to infinity on the right and left. As indeed it should from the familiar construction, since the distances from D' and O' to any point on the horizontal axis being equal, their difference is constant and equal to zero.

It appears, then, that a conic section may be defined as the locus of a point which is equally distant from a given point and from the circumference of a given circle. Boscovich defines it as the locus of a point so moving that its distances from a given point and from a given right line shall have a constant ratio.

The latter definition involves the conceptions of a rectilinear directrix, and a varying ratio in the cases of the different curves, this ratio being unity for the parabola, less for the ellipse, and greater for the hyperbola. The former involves the conception of a circular directrix with a ratio equal to unity in all cases; and the two definitions become identical in the construction of the parabola, which is in fact the only curve of which a clear idea is given by either of them. That of Boscovich has been given a prominence far in excess of its merits, being made the foundation for the discussion of these important curves, and this in a textbook whose preface contains the following true and emphatic statement, viz.:

"The abstract nature of a ratio, and the fact that it is a
compound concept, peculiarly unfit it for elementary
purposes."

The definition herein set forth has not been given in any treatise on the subject, so far as we have been able to ascertain. And it is presented with the distinctly expressed hope that it never will be, except as a mere matter of abstract interest.

Of this it may, like the other, possess a little, but both have the great disadvantage that, except in relation to the parabola, the idea which they convey to the mind of the curves to which they relate, if indeed they convey any at all, is most obscure and indirect; and of practical utility neither one can claim a particle.

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TABLE OF ATOMIC WEIGHTS.

(Issued December 6, 1890.)

By request of the Committee of Revision and Publication of the Pharmacopoeia of the United States of America, Prof. F.W. Clarke, chief chemist of the United States Geological Survey, has furnished a table of atomic weights, revised upon the basis of the most recent data and his latest computations. The committee has resolved that this table be printed and furnished for publication to the professional press. The committee also requests that all calculations and analytical data which are to be given in reports or contributions intended for its use or cognizance be based upon the values in the table. It would be highly desirable that this table be adopted and uniformly followed by chemists in general, at least for practical purposes, until it is superseded by a revised edition. It would only be necessary for any author of a paper, etc., to state that his analytical figures are based upon "Prof. Clarke's table of atomic weights of December 6, 1890," or some subsequent issue.

This table represents the latest and most trustworthy results, reduced to a uniform basis of comparison, with oxygen=16 as starting point of the system. No decimal places representing large uncertainties are used. When values vary, with equal probability on both sides, so far as our present knowledge goes, as in the case of cadmium (111.8 and 112.2), the mean value is given in the table.

The names of elements occurring in pharmaceutical, medicinal, chemicals, are printed in italics[1]:

[Transcriber's Note 1: ITALICS represented by surrounding with "_".]

Name. Symbol. Atomic Weight.

_Aluminum_. _Al_ 27. _Antimony_. _Sb_ 120. _Arsenic_. _As_ 75. _Barium_. _Ba_ 137. _Bismuth_. _Bi_ 208.9 _Boron_. _B_ 11. _Bromine_. _Br_ 79.95 Cadmium. Cd 112. Caesium. Cs 132.9 _Calcium_. _Ca_ 40. _Carbon_. _C_ 12. _Cerium_. _Ce_ 140.2 _Chlorine_. _Cl_ 35.45 _Chromium_. _Cr_ 52.1 Cobalt. Co 59. Columbium.[1] Cb 94. _Copper_. _Cu_ 63.4 Didymium.[2] Di 142.3 Erbium. Er 166.3 Fluorine. F 19. Gallium. Ga 69. Germanium. Ge 72.3 Glucinum.[3] Gl 9. _Gold_. _Au_ 197.3 _Hydrogen_. _H_ 1.007 Indium. In 113.7 _Iodine_. _I_ 126.85 Iridium. Ir 193.1 _Iron_. _Fe_ 56. Lanthanum. La 138.2 _Lead_. _Pb_ 206.95 _Lithium_. _Li_ 7.02 _Magnesium_. _Mg_ 24.3 _Manganese_. _Mn_ 55. _Mercury_. _Hg_ 200. _Molybdenum_. _Mo_ 96. Nickel. Ni 58.7 _Nitrogen_. _N_ 14.03 Osmium. Os 191.7 _Oxygen_.[4] _O_ 16. Palladium. Pd 106.6 _Phosphorus_. _P_ 31. Platinum. Pt 195. _Potassium_. _K_ 39.11 Rhodium. Rh 103.5 Rubidium. Rb 85.5 Ruthenium. Ru 101.6 Samarium. Sm 150. Scandium. Sc 44. Selenium. Se 79. _Silicon_. _Si_ 28.4 _Silver_. _Ag_ 107.92 _Sodium_. _Na_ 23.05 Strontium. Sr 87.6 _Sulphur_. _S_ 32.06 Tantalum. Ta 182.6 Tellurium. Te 125. Terbium. Tb 159.5 Thallium. Tl 204.18 Thorium. Th 232.6 Tin. Sn 119. Titanium. Ti 48. Tungsten. W 184. Uranium. U 239.6 Vanadium. V 51.4 Yterbium. Yb 173. Yttrium. Yt 89.1 _Zinc_. _Zn_ 65.3 Zirconium. Zr 90.6

--_Am. Jour. Pharm._

[Footnote 1: Has priority over niobium.]

[Footnote 2: Now split into neo-and praseo-didymium.]

[Footnote 3: Has priority over beryllium.]

[Footnote 4: Standard, or basis of the system.]

* * * * *

THE TANNING MATERIALS OF EUROPE.

The tanning materials of Europe are of an altogether different type from those of the United States. The population is so dense that the quantity of home materials produced is not nearly proportionate to the amount consumed, and consequently they must draw upon surrounding lands for their supply. The vegetation of these adjacent countries is of a much more tropical nature, and it naturally follows that the tanning materials are also of a different species.

Tanning materials may be divided into two great classes, viz.: Physiological and pathological.

PHYSIOLOGICAL.

The first class includes those tannins which are the results of perfectly natural or normal growth, and a growth necessary to the development of vegetation, for instance, bark, sumac, etc., whereas the second class contains those which are the results of abnormal growth, caused by diseases, stings of insects, etc. An example of this is the gall. Both of these classes are used to a great extent in Europe, while only the first division is in general use in the United States. We will first consider the physiological tannins.

_Oak Bark._--This material was, is, and will be for some time to come the main tanning material in use here in Europe. The advantages of the oak tannage are as fully appreciated here as in the United States. The European oak gives a light colored, firm leather, with good weight results, is comparatively cheap and of an excellent quality. The varieties are numerous, each country having its own kind. Those in most general use are:

_Spiegel Rinde_ (mirror bark).--This bark is well distributed throughout Europe, and is peeled when the tree has attained a growth of from 12 to 24 years. It is marketed in three grades.

_Reitel Rinde_--Is obtained from the same tree as the spiegel rinde, but after the tree has attained a growth of from 25 to 40 years.

_Alte Pische_ (old oak).--Obtained from the aged tree. It is not as valuable as the younger bark, and consequently brings a much lower price.

Spiegel rinde may be judged by small warts which appear on the shining surface of the bark. The presence of a great number of these, as a rule, indicates a high tannin percentage.

Bosnia has fine oak trees, the bark containing 10 to 11 per cent. tannin.

Bohemia has the _trauben eiche_ (grape oak).

France uses the kirmess oak, which grows in the south of that country and in northern Africa. Two grades are made, viz., root and trunk.

Tyrol has the evergreen oak--12 to 13 per cent. tannin.

Sardinia possesses a cork oak, which yields 13 to 14 per cent.

White oak is found throughout Europe, yielding 10 per cent. The price of oak bark varies a great deal. The assortment is much more strict than in the United States. In Austria it brings 4 to 5 fl., equal to $1.60 to $2 per kilo. (224 lb.); in Germany, 11 to 16 marks per 100 kilos.[1]

[Footnote 1: In the principal districts in America, removed from the cities, the price of oak bark is about $4 to $6 per cord or per ton of 2,240 lb. The hemlock bark, which gives a sole leather just as thoroughly tanned, but of a darker and reddish color, costs the larger tanners from $3 to $4 a cord.]

The above mentioned varieties are all used for both upper and sole leather. In Germany a great deal of upper leather is pure oak tannage, but one seldom finds a pure oak tanned sole leather; it is almost always in combination with other tannics.

_Pine Bark_--Is well distributed and is a very important tanning material. It bears the same relation to oak bark here as does hemlock in America, but its effects are quite different from hemlock. The best Austrian sorts are those of Styria and Bohemia, but that of Karuthen is also of good quality. The German pine comes from Thuringia to a great extent. The countries that consume the greatest amount of pine bark are Austria, Germany, Russia and Italy. The tannin contained varies from 5 to 16 per cent. Its use is almost wholly confined to the handlers, as its weight returns are not so satisfactory as oak or valonia. In case it should be used for layers it is always in combination with some better weight-giving tannic. For upper leather its use is limited.

The bark is always peeled from the felled tree, and often the woodman accepts the bark in part payment for his labor; he then sells the bark to the tanner or agents who go about the country collecting bark. It is generally very nicely cleaned. I would here like to correct a mistake which tanners often make in their estimations of the value of barks. A tanner usually buys the bark of southern-grown trees in preference to that of trees grown in northern countries, as it is a common idea that southern vegetation contains more tannin than that of the north. This is a fallacy, as has not only been proved by careful analyses, but may also be found to be an incorrect conclusion after a moments' thought. Those trees which flourish in southern countries grow very rapidly, and as tannin is necessary to the development of leaf structure, etc., it is absorbed to a greater extent than is the case with the slower-growing tree of the north. The tannin contained in the sap does not increase in the same ratio as does the rapid growth, and it follows that the remainder in the bark is less than in the tree of slower growth.

_Birch Bark_--Is at home in Russia, Norway, and Sweden. It is used for both upper and sole leather, but seldom alone. The bark is usually peeled from the full grown tree, and contains 4 to 9 per cent. tannin.

_Willow Bark_--May also be found in the above mentioned countries and also in Germany. This material is used for both upper and sole leather, and contains 6 to 9 per cent. tannin. It is a very delicate material to use, as its tannin decomposes rapidly.

_Erlen Rinde_--Is also a native of Germany, but is not used to any great extent. The same may be said of the larch, although this variety is also to be met with in Russia.

_Mimosa Bark_--Is obtained from the acacia of Australia. It is a favorite in England. The varieties are as follows: Gold wattle, silver wattle (blackwood, lightwood), black wattle, green wattle. The gold wattle is a native of Victoria. Its cultivation was tried as an experiment in Algeria and met with some success. The trees are always grown from seeds. These seeds are laid in warm water for a few hours before sowing. The acacia may be peeled at eight years' growth and carries seeds. The Tasmania bark is very good; that from Adelaide likewise good.

Sydney does not produce so good an article, but Queensland better. The bark is marketed in the stick, ground or chopped.

Madagascar and the Reunion Islands have also a mimosa bark.

The mimosa barks give a reddish colored leather, pump well and contain a high tannin percentage, 10 to 35 per cent.

Now we will consider the fruit tanning materials.

Valonia may truly be called one of the most generally used tanning agents at present employed in Europe. All countries consume it more or less. Valonia was first used in England about the beginning of this century. A few years later Germany began using it, and still later Austria introduced it. It is the fruit of the oak tree and is obtainable in Asia Minor and the adjacent islands. In form it resembles the American acorn, but in size it nearly trebles it. The fruit may be divided into two parts, namely, the cup and acorn, and the cup again divided into trillor and inner cup. The acorn only contains 10 per cent. tannin, whereas the cup contains from 25 to 40 per cent.

The percentage depends altogether upon the time of harvesting and the place of growth. The best valonia is derived from Smyrna, and is naturally the highest priced article. Valonia is worth from 22 to 28 florins ($9 to $11) per 100 kilos. (224 pounds) at present. The other provinces and islands from which it is obtainable are Demergick, Govalia, Idem, Ivalzick, Troy (this is the best); Metelino Island, the vicinity of Smyrna. The material sold in three grades--prime, mazzano; seconds, una aqua; thirds, skart.

The product of Smyrna generally averages:

Tons. Price.
Prime. 2,000 to 3,000 28 florins.
Seconds. 5,000 to 10,000 25 "
Thirds. 20,000 to 30,000 22 "

The _Metilino_ valonia is a product of a neighboring island, and is a very good article. It may be easily distinguished by its thin cup. It is harvested in September.

The _Candia_ valonia is nearly as long as it is wide, in contrast to the Smyrna, which is much wider than long. The recent harvest showed a return of 800 to 1,000 tons, but no assortment is made. A grade called the Erstlige is sold, this being the first which has fallen to the ground before maturing.

A peculiarity of the valonia is that it often strikes out a sort of sugar sweat, which gives the cup a less attractive appearance, but denotes the presence of large quantities of tannin.

Valonia is used almost wholly for sole leather, either alone or in combination with pine or oak bark or knoppern and myrabolams. The union of valonia and knoppern is that in most general use. Valonia gives the leather a yellowish appearance, as it deposits a great deal of yellow bloom. The leather is very firm and of good wearing qualities. The weight results are also excellent, as will be seen below. To sole leather there are usually given from one to three layers of valonia. The demand for valonia is increasing more and more every year, and the present outlook does not indicate any relaxation of its popularity. Its use for upper leather is very limited.

Myrabolams are mainly used in England and Austria, and give a nice light-colored leather, both upper and sole, although rarely used alone. Their main use is for dyeing purposes. They are indigenous to the East Indies.

Sumac is so well known that treating of it is superfluous. Its use is very extensive, and it is a general favorite for light, fine leather, which is mostly used for colors.

_Gambier_--Is in general use in England and to some extent in Germany.

_Catechu_.--Obtained from India, resembles gambier greatly. Its use is almost wholly confined to England. It is also consumed by the silk manufacturers in preference to gambier, for weighting purposes.

PATHOLOGICAL.

We now leave the physiological class and take up those tanning materials included in the pathological class, or those of abnormal growth.

_Galls_.--These are not consumed to any great extent at the present period, but formerly they were used quite extensively. The galls are found upon the leaves of the oak or sumac, etc. The direct cause of their growth is that a certain wasp (cynips galles) stings into the leaf and after depositing its egg, flies away. The egg develops into a larva and then into a full-fledged wasp, boring its way out of the gall which has served as a protection and nourisher. This accounts for the hole noticed in almost every gall. The different varieties include Aleppo. It is found upon the same trees as the valonia and contains 60 to 75 per cent. tannin; Istrian galls, 32 per cent. tannin; Persian, 28 to 29 per cent. tannin. Chinese galls, giving 80 to 82 per cent. tannin, are the results of the sting of a louse, and make a very light-colored leather. The dyers also use this material for coloring.

_Knoppern_--Belongs to the family of galls, and is a most important factor of commerce in Austria. The knopper is generally found on the acorn or leaf of the oak tree. The greatest quantity is derived from the steel oak of Hungary. The tannin contained varies from 27 to 33 per cent. Knoppern are not being used so much now as formerly, and consequently the amount harvested lessens from year to year. Its main use was and is in combination with valonia as layers for sole leather. Valonia gives better weight results than knoppern, and is replacing knoppern more and more every year. The combination of knoppern, valonia and myrabolams is also quite popular, and gives good results. Knoppern are seldom used alone, being generally combined with some other tannin. Austria is almost the only consumer at present, but Germany used it extensively formerly.

_Bark and Wood Extracts_--Are becoming general favorites throughout Europe, partly because of their weight-giving qualities and partly as the transportation costs so little; they can be used to strengthen weak bark liquors.

_Oak Extracts_--Are well liked, both wood and bark, and are used extensively. Slavonia furnishes a great deal of it.

_Chestnut Oak Wood Extract_--Is manufactured in quantities, and easily finds purchasers.

_Pine Bark Extract_--Is also consumed in goodly amounts.

_Quebracho Wood Extract_.--The wood is shipped from Brazil to Hamburg and other ports, and the tannin extracted there. Hamburg furnishes quantities of it.

_Hemlock Extract_--Is used in Russia, and seems to have taken a hold on the shoe buyers' fancies, as they now make imitations of it in color. The hemlock that is consumed is imported from America.

As most leather is sold by weight in Europe, the leather manufacturers aim to obtain as good weight results as possible, and often, I am sorry to say, do so at the sacrifice of quality. This is common to both upper and sole leather. Sole leather is nine times out of ten given false weight by forcing entirely foreign substances into the leather, such as glucose, barium chloride, magnesium chloride, resins, etc. Glucose and resin are also used for weighting upper leather. Leather is also weighted with extracts by overtanning. Leather buyers have become very wary of late and do not purchase large quantities before an analysis is made of a fair sample.

One more word before I close. The governments and private individuals in Europe cultivate and raise trees for both lumber and bark purposes. The forests are excellently cared for by efficient foresters, and the result is that the tanners obtain much cleaner and better bark, and of a very even quality. Would it not be a good idea if some individual, who would certainly earn the everlasting gratefulness of the tanners, would look into this matter, and see that not only the lumber side of our forest cultivation is not neglected, but that the bark also is preserved and cared for? Of course, we can obtain all the bark necessary at present and for some time to come, but the time will come when we shall certainly regret not having taken these steps, if the lumbermen and bark peelers go on devastating magnificent forests. Below will be found a table of weight results. Sole leather tanned with these materials gives for every 100 lb. green hide the following quantities of finished leather:

lb.
Oak bark 48 to 54
" extract 55 to 56
Pine bark 44 to 46
" extract 48 to 50
Willow 45 to 46
Birch bark and oak extract 49 to 51
Quebracho wood and extract 48 to 49
Valonia 52 to 56
Knoppern 51 to 53
Myrabolams 50
Knoppern, myrabolams and valonia 52 to 53
Hemlock 55

Specification of tanning materials used in different countries:

_France_. Oak bark (kirmess). Sumac. Chestnut wood extract. Quebracho " " Some gambier.

_Italy_. Oak bark. Pine " Sumac. Valonia.

_England_. Oak bark. Divi divi. Myrabolams. Valonia. Mimosa. Extracts { Oak bark and wood hemlock. Gambier. Cutch.

_Germany and Austria_. Oak bark. Pine " Willow bark. Valonia. Knoppern. Myrabolams. { Oak bark and wood. Extracts { Pine bark and wood.

_Russia._ Birch bark. Willow " Oak " Pine " Hemlock extract.

_Norway and Sweden_. Birch bark. Willow " Oak "

WALTER J. SALOMON.
--_Shoe and Leather Reporter_.

* * * * *

AN APPARATUS FOR HEATING SUBSTANCES IN GLASS TUBES UNDER PRESSURE.[1]

[Footnote 1: Read at the meeting of the Chemical Section of the Franklin Institute held March 17, 1891.]

By H. PEMBERTON, Jr.