pany. Elmer P. Morris, superintendent of construction, had charge of the party. The start was made from the car-barns at four o'clock in the afternoon, with fifty people in the car, all of whom were interested in the result.

The Consolidated Railroad Company are very conservative, and are not apt to spend much on experiments to improve their lines, unless assured of satisfactory results. They did not build a cable

before giving his opinion, and when he chose that of the ThomsonHouston Company, the railroad company did him the honor to close a contract with that company at once.

The present plant consists of one Corliss engine of four hundred horse-power, two Ball engines of two hundred horse-power each, and three Thomson-Houston electric generators of a capacity of 6,500 watts each. These generators furnish sufficient current to

operate eight motor cars of thirty horse-power each, and to light four horse-stables, three car- barns, and the generating station, about five hundred lights of sixteen-candle power each.

The road as at present equipped is two and eighty-five onehundredths miles long, and has three grades, each about sixteen hundred feet long with a three per cent rise. On the day of trial a motor car with a trailing car attached, loaded very heavily, made the distance in twelve minutes, and while on the grades the speed obtained was as high with the car added as that of the motor car by itself, showing conclusively that the Thomson-Houston motors are of sufficient capacity to do in the most satisfactory manner the work cut out for them. There is no unpleasant jerk or jar in starting the car, such as is found in many systems, and no scientific or mechanical knowledge is necessary to handle the car, which is controlled with ease.

The road when finished will be nearly six miles in length, making a round trip of twelve miles; and this, if proven successful, will be but a start in the rapid-transit line by the Consolidated Street Railroad Company. They have under way the plans for a one thousand horse-power plant for the hills, and the present plant will be enlarged to accommodate at least two more down-town lines. They also contemplate the equipment of from fifty to seventy-five cars, and expect to have the whole completed and in running order by the first of next year.

The recognition by this company of the merits of the ThomsonHouston electric railroad system is a very strong point in favor of that company; and as they gave practical demonstrations of their ability to fulfil their promises, they undoubtedly merit the honor thus paid them.

THE POETSCH FREEZING PROCESS IN MINING

OPERATIONS.

A BRIEF description of the freezing process devised by Herman Poetsch for sinking shafts in quicksands and other difficult ground was given in these columns in April last. The process has been successfully applied in sinking a shaft for the Chapin Mining Company at the Iron Mountain mines in Michigan. In this case, so thoroughly and effectively was the freezing done that, although the shaft was finished some two months ago, the earth surrounding it is still frozen solid in places.

The following description of the difficulties overcome and the methods employed in sinking the shaft mentioned is furnished us by the Patsch-Sooysmith Freezing Company of this city, who control the patents covering the process in this country.

A shaft fifteen and a half by sixteen and a half feet was to be excavated through quicksand to a ledge about a hundred feet below the surface. The mining company put the freezing pipes into the ground three feet apart, in a circle twenty-nine feet in diameter, and, with the exception of two of the pipes, down to the ledge. This proved to be a difficult task on account of the many bowlders encountered. A ten-inch casing pipe with flush joints was first drilled down by various means, a drill being worked within the pipe when necessary and the material removed by jetting or by a sand pump. The casing pipe being once down to the ledge, a freezing pipe was placed inside, and the outer casing pipe drawn up and used for the next pipe. The freezing pipes left in the ground were eight inches in diameter, the lower ends being closed. Inside of these eight-inch pipes were placed pipes one and a half inches in diameter, open at the bottom. These inner pipes, as well as the outer pipes, were connected together at the top of the ground, as shown in the pipes at the left of the illustration, forming a complete circuit, through which a cold brine was circulated.

The brine used was a solution containing about twenty-five per cent of calcium chloride, which has a very low freezing point. The brine was cooled with an ice machine, having a refrigerating capacity of fifty tons of ice per day. The ammonia was compressed to about 135 pounds per square inch, and cooled by passing through coils immersed in water kept cold by pumping from a brook. Then the ammonia was allowed to expand through coils immersed in the brine and finally returned to the compressor.

The temperature of the expanded ammonia was such as to cool the brine to a few degrees below zero, Fahrenheit. This brine,

being circulated through the ground pipes, was raised in temperature about 2° F. After forty days' freezing, an ice wall ten feet thick was formed around the shaft. The excavation, commenced soon after starting the ice machine, had in the meantime reached a depth of forty feet. Thirty days more sufficed to reach the ledge. The shaft was, for convenience, curbed as the excavation proceeded. This was, however, not necessary, as the walls would have stood vertically throughout the whole depth very well. The temperature of the air within the shaft was generally below the freezing point, and there was no indication of the exposed material thawing. The curbing was made of horizontal sets of timbers, sixteen inches square, placed two feet apart, with four-inch vertical plank behind the timbers. The cross walls were put in place afterwards.

The timbering was supported from one set to another by bolts placed near the corners of the shaft, the whole system being suspended from cross timbers at the surface of the ground. The unfrozen area within the shaft grew less as the actual running time of the freezing machine increased. By the time a stratum of bowlders was encountered, the frozen area reached nearly across the shaft; but when quicksand containing a large percentage of water was passed through, the unfrozen area was greater. The reason of this is readily understood when it is remembered that the specific heat of water is about five times as great as that of any of the other materials, and therefore the strata containing most water would require more cold and would be longer in freezing.

The hardness and appearance of the fractures of the frozen quicksand approached those of sandstone. Granite bowlders embedded in it showed a decided tendency to fracture across rather than break loose. The tensile strength of the frozen ground, as determined by a cement-testing machine, was equal to that of the best neat Portland cement, and varied from 350 to 450 pounds per square inch, and its strength against crushing, as determined from inch square cubes, was 850 pounds per square inch. This furnishes data from which the strength of the surrounding frozen wall may be computed as an arch. An ice wall ten feet thick will be found sufficiently strong for any case likely to occur. Near the bottom the freezing extended within the circle solidly ten feet from the pipes. It is not known how far it extended outside, as no borings could be made through it. A test pit was sunk outside the shaft as far as the water would permit (some fifteen feet), and from this it appeared that the freezing extended outwardly from the pipes about three-fourths as far as within the circle.

The material was mostly loosened by picks and chisel bars. Powder was used for blasting for a considerable time, but this was discontinued for fear the concussion might injure the pipes or fracture the wall. The material was hoisted out by an iron bucket, which also took out the water that stood in the unfrozen centre. There was no appreciable inflow of water until the excavation had reached nearly to the ledge, when a small amount was noticed.

On reaching the ledge, it was discovered that it was so fissured and disintegrated as to allow water to come in under the frozen wall at a corner in the vicinity of one of the pipes that did not extend to the ledge. The shaft was allowed to flood, water being pumped into it at the same time to prevent as much as possible the flow of water through the opening. An eight-inch freezing pipe was put in place in the shaft, the foot being directly at the opening, and earth was piled around it, the purpose being to freeze the leak off. Then cold brine was circulated through the whole system of freezing pipes for ten days uninterruptedly, when the water was pumped out, and the seam was found to be quite closed; but there was still a small amount of percolation through the ledge, requiring occasional pumping to clear the shaft; ice had collected several inches thick on the side shaft, and several feet in the corner, where the extra freezing pipe was placed.

The work of removing the earth which had been thrown in and the clearing up of the bottom continued for two weeks, when the water from the ledge increased at such a rate that it was decided to lay short auxiliary freezing pipes against the leaks and freeze the ledge itself. This was done, the shaft was flooded again, and the brine circulated thirty days. When the water was pumped out, the leakage was found to be small, and excavation was proceeded with. The soft, shaly rock was removed till a hard bear

ing was obtained for the timbers, and the timbering was completed from the surface of the ground to the excavated depth.

The obvious remedy for inflow from the rock will be in the future to put the pipes far enough into the ledge to freeze off the surface seams. Pipes are now being put down for a coal mining shaft at Wyoming, Pa., and they will be put several feet into the rock, which will no doubt intercept all troublesome percolation.

This operation of this process was the first application on any considerable scale in the United States. Water is the engineer's most troublesome enemy, and its conversion into a barrier of defence is a triumph of engineering as effective as it is novel. This process can be applied to excavations for bridge piers, to tunnels, and to other general work of a difficult and expensive character as well as to shafts. But in shaft work alone it should be invaluable, as by it numerous valuable deposits of coal and other minerals, now inaccessible on account of overlying strata of water-bearing materials, can be reached, as in the case of the Chapin mines, and in those Belgian coal mines which first led Mr. Poetsch to devise his process.

THE PRODUCTION OF SUGAR.

YESTERDAY the formation of sugar by plants, says Ward Coldridge, in Knowledge, was one of the mysteries of nature. Chemists and botanists, while they knew that ordinary chemical attractions must be the cause, were yet completely in the dark as to how these forces worked. They realized that plants started with carbonic acid and water, and from these waste products of animal existence built up in some unknown way the complex compound, sugar. From the deadly choke-damp to the luxury sugar was a great transformation. The plants could thus build, but men of science could not comprehend the process.

To-day, as the result of some brilliant researches, the explanation has been found. A simple compound, the formation of which by the plant can be readily accounted for, has been transformed into a sugar. To understand the process, it must be realized that abundant evidence proves that plants promote processes which are the opposites of combustion or oxidation. Plants liberate oxygen from its compounds, and absorb that with which it was previously combined. They can liberate oxygen from so stable a compound as carbonic acid, and in water find a source for the hydrogen which is essential to their development. The products which could thus be formed are, respectively, from carbonic acid, the lower oxide of carbon and oxygen; from water, the gases hydrogen and oxygen. Experiments have shown that under the influence of the silent electric discharge, and even without it, carbon monoxide and hydrogen combine to form a simple compound, formic aldehyde, which is immediately connected with the formic acid of the ant and of the stinging-nettle. So the changes which occur in the plant under the combined influence of sunlight and chlorophyl may be represented in symbols as follows:

When

This formic aldehyde was the substance experimented on. it was suitably treated in the presence of the hydrate of lime, Ca (HO), it was induced to combine with itself and to form another compound. The latter is composed of the same ultimate indivisible particles (atoms) and in the same proportions; but they are now differently arranged side by side, and with a larger number in the unit aggregation which chemists call molecules. This compound has now been finally proved to contain not one, but at least two or three members of the family of substances, carbohydrates, to which sugar belongs. Thus in our laboratories can now be imitated the process of which plants previously held the secret.

While, however, the fact is marvellous that a sugar has been obtained artificially, it must be remembered that the process is absolutely uneconomical, for the yield is very small. This remark, too, applies to another process of artificial production. The sweet viscid liquid, glycerin, and its stinking, irritating offspring, acrolein, which gives the nasty smell of burning fat, have both been transformed into sugar; but the quantity obtained is very small in pro

portion to the glycerin or acrolein used. The importance of these researches lies in the fact that they show how the chemical changes which characterize the vital action of the plant can be imitated with dead matter, and that, further, they shed a bright gleam of light on the hitherto obscure question of the arrangement of the indivisible particles, atoms, within the compound particles, the molecules of these substances.

Our supply of sugar will always be drawn from the vegetable kingdom, the synthetic laboratory of nature. Many plants work hard and economically at the production of sugar, and form it in quantity. It occurs in all parts of plants, root, stem, leaves flower, fruit, and seed. In some grasses it is very abundant, in the sugarcane, in the sorgho grass, and in the young shoots of the maize. In the common carrot and parsnip, and especially in the fleshy beet, large quantities are contained. But for its commercial extraction two sources are chiefly used the sugar-cane and the beet-root, and a third is of growing importance, the sorgho grass.

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The sugar-cane has far greater natural advantages than the beet-root. At one time the former held the field without a rival. But during the Napoleonic wars, France was deprived of her supply of sugar, and she was driven to produce her sugar at home. This resulted in the commencement of the beet-sugar industry, and thus amongst the secondary results of war must be reckoned bounty-fed sugar. To judge of the economic aspects of the two industries, many factors have to be taken into account. When that has been done, this balance will be found distinctly in favor of the cane. Sugar-canes contain sufficient sugar to yield seventy to eighty per cent of their weight of juice, in which there is some twenty per cent of sugar, Beet-roots, as an extended series of investigations have shown, possess a percentage of sugar varying from seven to a maximum of under fourteen, and on the average about eleven. Now an acre of land which can be used for beetgrowing will be rented for, say, £4 per annum, while in the colonies an equal area of cane-producing land will be rented for about onetenth of that amount.

Further, a great divergence is found in the quantity of beet and cane which two equal areas can grow. For instance, in the environs of Magdeburg, an acre will yield about ten hundred-weight of sugar; whereas, in the home of the sugar-cane, some forty to fifty hundred-weight can be obtained. Then other items in the cost of production have to be considered; the difference in wages in the two regions, the difference in the cost of fuel, in Europe where coal is necessary, in the colonies where the waste matter of the cane supplies the whole, or nearly the whole, of the fuel required. One can thus realize the grounds on which the Brazilian commission on the sugar industry reported, that, in their opinion, "the cost of production may be reduced in Brazil to such a degree as to defy competition, and the struggle between cane and beetroot must become ominous to the latter, which thrives only by the artificial advantages which European countries have devised."

Hitherto the artificial advantages have been on the side of the European countries; but now the greatly improved means of transit, and the diffusion of knowledge, are raising the colonists to a position nearer equality in these respects, of course excluding bounties. And by this time the colonial sugar planter has learned a severe lesson. He understands that, while nature has showered her gifts on him with a lavish hand, she mercilessly punishes him for carelessness and lack of promptitude. For if he cuts his canes, they must within a few hours be crushed and extracted; if he is negligent, and leaves them for only two days, fermentation rapidly ensues under the conditions of tropical temperature, and the canes turn sour and must be thrown aside for fuel. In this way nature has fined men whole fortunes.

FATTENING LAMBS.

AT the Cornell Agricultural Experiment Station some experiments have been carried out recently on the effect of different rations on fattening lambs, under the direction of Professors J. P. Roberts and Henry H. Wing. These experiments were, in the main, a continuation of those carried on at this station one year ago, and very nearly the same foods were used, none of them being out of the reach of the general mass of farmers.

The period of feeding lasted five full months, from November 25, 1888, to April 25, 1889. The lambs, twelve in number, were selected from a lot that had been picked up in the surrounding country for shipment. They were coarse wool grades, Shropshire or Southdown, dropped late the previous spring, and had evidently been scantily fed during the summer. They were not such animals as would have been selected to give the best financial results, but being thin in flesh and fairly uniform, were well adapted to the purposes of the experiment. The twelve were closely shorn, and then divided into four lots of three each, in such a manner as to have as nearly as possible an equal weight in each lot. Three lambs were used in each lot, so that if for any reason there should be an accident to one there might be two left at the end, from which to gather data in regard to the effects of the rations.

The lots were numbered respectively III, IV, V, and VI, and each lamb was labelled with a separate numbered ear-tag, so that data in regard to increase in weight, etc., could be collected individually and by lots. The experiment progressed satisfactorily from beginning to end, with but two exceptions.

Lot III was fed what may be called a carbonaceous ration. The lambs were given all the timothy hay and whole corn they would readily eat, and in addition about a half pound of roots each per day. Turnips were fed as long as the supply lasted, after that mangels were used.

Lot IV was fed a nitrogenous ration, although it was not so excessively rich in nitrogen as that used by some experimenters in trials of this kind. The grain ration was made up of two parts wheat bran and one part cotton-seed meal. A pound per day per lamb of this mixture was fed at first; afterward it was somewhat increased or diminished, as the needs of the case required, the object being to feed about all that would be readily eaten. This lot received clover hay instead of timothy, and roots, as lot III.

Lot V was fed an intermediate ration. The grain part was composed of three parts corn and one part each of wheat bran and cotton seed meal. It was eaten in about the same quantity as lot IV. Timothy hay was used for this lot, and roots were fed as in each of the others. Lot VI was fed the same as lot V, except that they received no roots at all.

The lambs had access to water the whole time. In the winter it was warmed to about 80° before being offered them. The weight was obtained in the following manner. A pail of water was weighed and placed in the pen, where it remained till the next morning, the sheep drinking whenever they wished. Each morning the pail, with whatever water remained in it, was weighed back, the difference in weight being the amount consumed. A fresh pailful was then weighed out, and the process repeated. This was kept up during the whole course of the experiment. The water was warmed when it was first put in, and during the cold weather the lambs soon learned to take nearly all their water as soon as fresh water was given them. From the first a marked difference was seen in the amount of water consumed by the different lots, and this difference continued through the whole course of the experiment. The total amount of water drank was as follows: Lot III drank 308 pounds, or 1.03 pounds per lamb per day; lot IV drank 1,185 pounds, or 3.95 pounds per lamb per day; lot V, 735 pounds, or 2.45 per lamb per day; lot VI, 847 pounds, or 2.82 per lamb per day.

The very much larger quantity of water consumed by the lambs fed a highly nitrogenous ration is at once apparent. It will be seen that lot IV drank nearly four times as much as lot III (fed carbonaceous food), and about 60 per cent more than lot V. These three lots were all fed roots in equal kind and quantity, so that it would seem that the different amounts of water consumed must be due to the nitrogen in the ration.

Lots V and VI were fed on the same ration, except that lot VI had no roots. Probably for this reason they drank about 15 per cent more water. The lambs fed on nitrogenous food, or lot IV, made much the largest average gain, and those fed on carbonaceous food, lot III, made the smallest gain, though not very much smaller than lot VI. Animal individuality, a very perplexing consideration in all work of this kind, showed its influence very strongly.

Notwithstanding the gain in live weight was very} markedly in

favor of the lambs fed on nitrogenous food, it is when we come to compare the amount of gain in relation to the amount and cost of the food consumed that the most striking figures are brought out. Both in the amount of food consumed for one pound of gain, and the cost of gain per one hundred pounds, the advantage is very markedly in favor of lot IV, the lot fed on nitrogenous food. It costs a little more than a cent and a half per pound, or twenty-six per cent more to put a pound of gain upon the lambs that were fed on corn, timothy hay, and roots than it did to put a pound of gain on those that were fed wheat bran, cotton-seed meal, clover hay, and roots.

The lambs were shorn Nov. 15, or ten days before the beginning of the experiment. They were shorn again the day before they were slaughtered, so that the wool obtained was the growth of 160 days. The weight of the wool from both lambs in each lot was, lot III, 4.25 pounds; lot IV, 7.31 pounds; lot V, 6.63 pounds; lot VI, 6.19 pounds; the last three lots showing an increase over lot III of 72, 56, and 46 per cent respectively. This coincides with the results of the experiments last year, in that nitrogenous food seems to largely affect the growth of wool. It seems to show further that even a small increase in the nitrogenous matter of a ration has a decided influence on the growth of the wool, for lots V and VI, whose ration was intermediate in character, gave very nearly as much wool as lot IV. In the experiments of 1888, already referred to, the percentage was not so great in favor of the lambs fed on nitrogenous food.

The lambs were slaughtered on April 25. The blood was carefully caught in a clean pail, and it and all the important internal organs were weighed. The carcasses were hung up in a cool place to stiffen for two days, and were then cut up, and the parts carefully examined. Before they were taken down, however, they were weighed and most carefully inspected by the different members of the staff. The most striking difference that was apparent, as the carcasses hung upon the hooks, and after they were cut up, was the evident leanness of the two belonging to lot IV, which had been fed nitrogenous food. The kidneys were not covered, and there was very little loose fat next the skin, while in all the other carcasses the kidneys were more or less completely covered, and there was a layer of tallow of greater or lesser thickness between the skin and body. The carcasses of lot III had the most of this tallow. The same thing is shown in the amount of caul fat and kidney fat. While an expert butcher would have undoubtedly selected the carcasses of lots V and VI as furnishing the most saleable mutton, the carcasses of lot IV had little or no unpalatable adipose matter, and those of lot III showed much the largest percentage of waste fatty matter about the root of the tail and in the flanks. The weight of evidence of all of the experiments at Cornell, together with results obtained by other experimenters in the same field, seems to show: that corn, as an exclusive grain ration, does not give the best results, either in amount, quality or economy of production, when fed to growing or fattening animals; that the amount of water drank, especially in the case of these lambs, is a pretty certain indication of the rate of gain; and that the production of wool is very greatly dependent upon the nitrogen in the ration. The value of the manure made from the animals fed is a matter of prime importance, to all eastern farmers at least. And often the manure left on the farm represents a large part, if not the whole, of the profit made from feeding a lot of animals. For this reason there were calculated the manurial value of the rations fed the different lots. From this it appeared that while the first cost of the ration of the nitrogenous fed sheep was larger than that of the carbonaceous, yet when the value of the manure is subtracted, the cost of the former is less than half of the latter.

PEARL OYSTERS.

THE presence of nodules or tubercles on the interior surface of the shells or valves of lamellibranch (bivalve) mollusks is of frequent occurrence. These excrescences are nacreous or otherwise, according to the character in this respect of the shell in which or upon which they occur. They are found alike in fresh-water and marine species. In the pond and river mussels they are chiefly due to interior causes; in marine forms, like the cockles, mussels, the

scallops, etc., these formations are generally traceable to exterior causes. It is often the case that specimens of the large scallop of the New England coast are so burrowed into by a species of sponge that nearly the entire inside surface of the valves will be roughened with sharp, thickly-set pustulæ. In all the marine species in which those nodules occur it will usually be found that the substance of the shell has been bored into from the outside by either a species of pholad or lithodomus.

Neither of these forms are, properly speaking, either parasites or commensals. They are, more definitely, "domiciliares," as stated by Mr. Robert E. C. Stearns of the Smithsonian Institution, and excavate their burrows, not for the purpose of getting at the softer parts of the mollusk upon whose shell they have " squatted in order to use said softer parts as food, but solely for the purpose of a residence or domicile.

The burrows of these shell-boring pholads and lithodomi are at first quite small, increasing in size in the same ratio as the burrower increases in age or in growth. After a while the depth of the boring is equal to the thickness of the shell in which it has been made, and the occupant of the latter, in order to keep his own shell intact and maintain the integrity of his own domicile, commences depositing layer upon layer of nacreous or porcellaneous matter, as the case may be. In keeping pace with the continued encroachments of the domiciliary squatter upon the outside, this deposit finally becomes a more or less conspicuous protuber

ance.

Sometimes these nodules or tubercles are due to some foreign inorganic matter, a particle getting in between the mantle of the mollusk and the inner surface of its shell. In such cases it is, we may say, at once plastered over, and thus fixed upon the surface of the valve. Free concretions, i.e., unattached or non-adherent nodules, are, as is well understood, caused by some particle, organic or inorganic, becoming in some way lodged exclusively in the soft parts of the body of the mollusk, and so far away from the surface of the shell as not to admit of its being cemented to it.

No doubt many of the mollusca, both gastropod and lamellibranch, contain or are inhabited by true parasites. In certain species of fresh-water mussels a species of water mite has been detected, and sometimes thread worms and other forms occur.

A small species of crab, an epicurean no doubt, finds a salubrious habitation in the common oyster, but parasites of any considerable size appear to be rather rare. Besides the species above referred to, another small crab is sometimes found in the common mussel and the large scallop before mentioned. It is doubtful, however, whether these crabs are really parasites or only commensals, though probably the former.

There is, however, evidence of the occurrence of fishes of two species as parasites in the true pearl oyster, or mother-of-pearl shell, not by the presence of the living fish, or even by dead specimens of "fish in the flesh," if we may use so convenient a paradox, but by their entombed remains in the form of nacreous nodulæ or tubercles on the shells or valves of the said mollusk.

At a meeting of the Zoological Society of London June 1, 1886, Dr. Günther exhibited a specimen of a small fish of the genus fierasfer embedded in a pearl oyster, and said: "This specimen is an old shell, in which there is imbedded, behind the impression of the attractor muscle, a perfect individual of a fish belonging to the genus fierasfer. The fish is covered by a thin layer of pearl substance, through which not only the general outlines of the body but even the eye and the mouth can be seen. The parasitic habits of fierasfer are well known. The fish, instead of introducing itself into the cavity between the two halves of the mantle, penetrated between the mantle and the shell, causing irritation to the mollusk. which the latter resented by immediately secreting the substance with which the intruder is now covered. It is remarkable to note that the secretion must have taken place in a very short time, at any rate before the fish could be destroyed by decomposition."

After entering the shell, which of course must be at such time as the valves are partially open or gaping, these fishes find no obstruction to their course as they push their way towards the interior between the mantle and the smooth inner surface of the valves until they approach the adductor muscle, and here they find a barrier which most likely causes them to expend somewhat greater ac