fitted, viz.: one to the high pressure end of the after cylinder, one to the intermediate end of that cylinder, one to the top and one to the bottom of the forward, the low pressure cylinder. The first set of diagrams was taken at 8.22 A. M. The first reading of the counter at 8.30 A. M. From this time until 5.45 P. M. the counter was read at the hours and half hours, and sets of diagrams were taken at the quarter past the hour, and at the quarter to the hour. The time when each sack of coal was lowered into the stokehold was noted, and also the time when the stoker commenced to use the contents of each sack. The last shovelful of the fifteenth sack was put on at 5.18 P. M., and it was decided to stop the trial as soon as the coal then in the fire was exhausted. I determined to let the engines run on until they stopped of themselves, and to take indicator diagrams, first at each quarter of an hour and then at each five minutes during the time they were gradually stopping. The quarter hour diagrams were taken until 6.30 P. M., when the engines were making 124 revolutions, and the five minutes diagrams were taken until the engines came to a stand at 7.23 P. M. or 12 hours 3 minutes after their start in the morning. The water in. the boiler was pumped to the same level in the gauge as that at which it had stood in the morning and the height of water in the hot well was noted. The mean revolutions from 8.30 A. M. to 6.30 P. M., 10 hours, were 130.77 per minute, and from the first start to the same time being 11 hours 10 minutes, the mean revolutions were 130-4 per minute. An experiment was made as to the transmission of heat through the boiler casing. This was carried out by placing the bulb of a thermometer in contact with the top of the casing, the bulb being covered over with cotton waste; the result was that at the end of one hour the thermometer stood at 125 degrees Fahr. From the start at 7.20 A. M. to 6.30 P. M., 11 hours and 10 minutes, the engines developed an average gross indicated horse-power of 80·55, but from 6.30 to the time, 7.23 P. M., that the engines stopped of themselves from the fire having burnt itself out, the power was of course gradually diminishing. This being so I have calculated the whole work from first to last in foot-pounds; these amount to 1,828,291,466 foot-pounds, equivalent to 923·38 horse-power if exerted for one hour. I estimate the 50 pounds of wood as of about one- The gross indicated horse-power developed during the trial being equivalent to 923-38 horse-power exerted for an hour 1697923:38 = 1.83 pounds of coal per horse power per hour, including the coal used in getting up steam. As a check upon the foregoing from the time when the first shovelful of the fourth sack of coals was put on the fire, namely, at 7.50 A. M. to the time when the first shovelful of the fifteenth sack of coals was put on the fire, namely, 4.45 P. M., i. e., 8 hours 55 minutes, the engines exerted an average of 80.9 horse-power; this gives the consumption per horse-power per hour at 17 pounds, assuming the fire was uniform at the commencement and end of these times. The loss of water for the whole 12 hours was 23 gallons. The engines worked with the most remarkable smoothness and regularity, as with the exception of tightening up the bolts of two glands about an hour after the start, there was not a spanner or hammer or any tool used about the engines during the 12 hours the ship was under way, nor was there a single handle connected with the engines shifted. The link-motion was in full gear the whole while, and the stop valve and throttle valve remained, as I have said, sealed up and unmoved. Water was allowed to circulate on the thrust-block, but there was not a heated bearing anywhere. The amount of lubrication was small, involving an expenditure of about one gallon of lard oil, while cylinder and slide lubrications are in the Perkins system inadmissable and with the metal used unnecessary. The engines were thoroughly steady, no straining or racking of any kind, in fact it is impossible for any pair of engines to have worked in a more thoroughly satisfactory manner, so far as all external evidence of working was concerned, and there were no sounds to lead to any other belief than that of all being satisfactory within. I hope on the return of the Anthracite from America to have an opportunity of seeing the engines opened, and of thus observing their condition after some thousands of miles of steaming, and I should also be glad to have an opportunity of retesting the consumption. At the conclusion of the trial my assistants took away the four indicators and the spring balance with which the coals were weighed. All these have been tested with the result that the balance and the 100 pound spring (used in the high-pressure cylinder indicators) and some of the lighter springs, are absolutely accurate, and that the variations in the others are too trifling to call for any allowance in calculating the mean pressures. It may be well to state that the mean pressures of the various diagrams (of which there were 128 in all) have been ascertained by dividing the areas of the diagrams, obtained with the planimeter, by the lengths of the diagrams. This is a thoroughly accurate mode, while the plan commonly followed of measuring the heights of the diagrams at a number (usually ten) of places is one which ordinarily gives a pressure in excess of the truth. It would be an investigation of considerable interest in an engineering point of view if a vessel fitted with first-rate compound engines of the ordinary construction, and working, say, at 70 pounds pressure in the boiler and indicating something about the same power as those of the Anthracite, viz., from 70 to 90 horse-power, could be tried in a precisely similar manner to that in which the Anthracite was tried. In conclusion I wish to say that I esteem myself particularly fortunate in having obtained the friendly co-operation during the run of Mr. William Rich, of Messrs. Eastons and Anderson, whose long experience in engine trials rendered his assistance of the greatest value, and to whom I beg leave to express my best thanks. I have his authority for saying that he entirely concurs in this letter of report. I am, gentlemen, your obedient servant, Ammonia in Vegetables.—H. Pellet has lately found appreciable quantities of ammonia in various kinds of grain, as well as in beet root. In wheat the weight of ammonia is one-tenth as great as that of the ashes. He thinks that magnesia and phosphoric acid enter into vegetables under the form of an ammoniacal magnesian phosphate, which is very soluble in all vegetable acids. He is now studying the effects of ammoniacal manures, and of nitrogen, under different forms, upon the amount of ammonia in vegetables.-Comptes Bendus. C. THE MANUFACTURE OF BESSEMER STEEL AND INGOT IRON FROM PHOSPHORIC PIG. By C. B. HOLLAND and A. COOPER, Sheffield. Before entering upon the subject of our paper it might not be out of place to consider for a moment what is steel and what is ingot iron. Steel has been defined as "an alloy of iron and carbon which is capable of being cast whilst in a fluid state into a malleable ingot," and all other elements usually found in the steel of commerce, such as silicon, sulphur and phosphorus, may be regarded as impurities, and are more or less hurtful. In like manner, ingot iron may be defined as an iron which is capable of being cast whilst in a fluid state into a malleable ingot, and other elements found in it (including carbon) may in this case also be regarded as impurities. It follows, then, that those steels and ingot irons are the best and purest which contain the noxious elements in the least quantities, no matter whether they be produced from the finest brands of Swedish and hematite, or from common iron containing from 1 to 2 per cent. of phosphorus. And we think all will agree, if it can be shown that steel and ingot iron can be produced from the latter kind of pig of the same chemical composition, and capable of standing the same mechanical tests as that produced from the purer irons, that one is as good as the other for all purposes. It is not our intention to occupy the time of the Institute by referring to any of the numerous papers that have been written, and the theories that have been propounded, during the last eighteen months, on the dephosphorization of iron by the Thomas and Gilchrist process, interesting and instructive as many of them are. It will be sufficient to say that notwithstanding the great strides that had been made in the development of the process at the works of Messrs. Bolckow, Vaughan & Co., under the able direction of Mr. Richards (who must always be regarded as one of its earliest pioneers), and the very satisfactory results obtained by that company in the manufacture of steel from Cleveland pig-iron up to the early part of November last, before we had seen the process in operation, there appeared to us certain difficulties which we feared would greatly retard its successful working from a commercial point of view. The first of these may be regarded as a technical one, and had reference to that part of the operation now well known as the "after-blow." Assuming, as we did, all the metalloids, with the exception of phosphorus and sulphur, to be oxidized before the commencement of this period, it seemed doubtful to us whether this would be practicable (having no definite point at which we could safely stop blowing corresponding to the drop of the carbon flame in the ordinary process) to burn out the whole of the phosphorus regularly, without sometimes carrying the operation too far, and thereby oxygenating the charge. And this, as all steelmakers will agree, is very apt to give trouble. Again, we had our misgivings about the gathering at the nose, concerning which we had heard so much, and the delays which we thought must necessarily result from the indispensable and repeated turning down of the converter for sampling. It was at this time (early in November last year) that we were invited to see the process at the Horde Works in Westphalia, and through the courtesy of Mr. Pink, the manager of the Steel Works, our representative was not only shown the process in operation, but every information respecting the difficulties that had been experienced up to that time, and the means which had been employed to overcome them, was very kindly given to him by that gentleman. From the working at Horde it was apparent that the phosphorus was eliminated with regularity-there were no violent reactions on the addition of the spiegel, showing that the metal was not oxygenated to any great extent, and the steel made was of a mild quality, and very malleable. On November 20th we commenced to work the process in Sheffield, using a mixture of White Lincolnshire and No. 4 forge irons. By sampling during the after-blow, we were enabled not only to remove the phosphorus in a very satisfactory manner, but also to make good and malleable steel; but the gathering of the slag and metal at the nose of the converter at first proved such an obstacle to rapid working, that although we employed men with long bars to fettle after each operation, at the end of from twelve to eighteen blows we were compelled to stop, allow the converter to cool down, and cut out the accumulation. At this early stage we were of opinion that by increasing the area of the nose we should get a decreased pressure of gases, and consequently the slag and metal would not be carried up so high, and that this would remedy the evil. Our experiment proved to us conclusively the fallacy of this, for after altering the shape of our con |