Scientific Notices. REPORT OF TRANSACTIONS OF THE INSTITUTION OF CIVIL ENGINEERS. (Continued from page 67, Vol. XXI.) March 8, 1842. The PRESIDENT in the Chair. Description of the Tanks for Kyanizing the Timber for the permanent way of the Hull and Selby Railway." By John Timperley. Upon the recommendation of Messrs. Walker and Burges, the Engineers, it was determined that the sleepers of this railway should be kyanized in close vessels, using exhaustion and pressure, instead of in the open tanks usually employed. The present communication, which includes a description of the kyanizing vessels, and an account of the various circumstances connected with the operation, commences by describing the apparatus, as shown by the accompanying drawing, to consist of two tanks, a reservoir, two force pumps, and a double air pump. The tanks are cylindrical, with flat ends, and are made of wrought-iron plates, nearly half an inch in thickness; they are 70 feet in length, and 6 feet in diameter: at each extremity is a cast-iron door, flat on the outside, and concave on the inner side, provided with balance weights for raising and lowering it. Each end is strengthened by five parallel cast-iron girders, whose extremities are held by wrought-iron straps, riveted on to the circumference of the tanks. Notwithstanding the great strength of these girders, several were broken by the pressure applied during the process. The vessels are lined with felt, upon which is laid a covering of close jointed fir battens, fastened with copper rivets; this precaution is necessary to prevent the mutual deterioration which would arise from the contact of the iron and corrosive sublimate. There was originally only one brass force pump, 2 inches diameter, and 6 inches stroke; this being found insufficient, another was added of 4 inches diameter, and henceforward a pressure of 100 lbs. per square inch was easily obtained. The air pump is 10 inches diameter, and 15 inches stroke. Its construction is of the ordinary kind. The author gives, in an appendix to the paper, a minute description of the various parts of the apparatus, with the details of their dimensions and weight. The process is simple and rapid; the corrosive sublimate is first mixed with warm water in a trough, in the proportion of 1 lb. of the former to 2 gallons of the latter; the clear solution is then poured off into the reservoir, where water is added till it is diluted to the proper point, which may be ascertained by a hydrometer; a more perfect test is the action of the solution upon silver, which it turns brown at the requsite degree of saturation. The operations of exhaustion and pressure, employ eight men for five hours, the whole process occupying about seven hours, during which time from 17 to 20 loads are kyanized in each tank. It is desirable that the timber should remain stacked for two or three weeks after kyanizing, before it is used. It was found that about lb. of corrosive sublimate sufficed to prepare one load (50 cubic feet) of timber. About 337,000 cubic feet of timber were kyanized, the average expense of which, including part of the first cost of the tanks, was about 5d. per cube foot. The timber was tested after the process, and it was found that the solution had penetrated to the heart of the logs. The paper contains some interesting tables, exhibiting the quantity of solution taken up by different kinds of wood with and without exhaustion; from these it appears that the saturation per cube foot, in the latter case, did not exceed 2.25 lbs. with specimens of Dantzic timber, whereas it ranged between 12.24 lbs. and 15-25 lbs. with pieces of home-grown wood. The author observes that this striking difference may be partly due to the greater compactness of the foreign timber. Appended to this communication is a correspondence between Mr. J. G. Lynde and Mr. James Simpson, relative to the best tests of the presence of corrosive sublimate, accompanied by letters from Mr. Colthurst and Dr. Reid; the former of these describes the process of kyanizing adopted on the Great Western Railway, and the latter suggests the three following tests; 1st, VOL. XXI. K Dilute hydro-sulphuret of ammonia; 2nd, A strong solution of potassa; dilute nitric acid and proto-muriate of tin, also gold-leaf with this solution; and 3rd, Iodide of potassium. Directions are given for the application of these tests. Mr. Lynde also mentions the use of a solution of nitric acid, and by the application of hydriodate of potash, detecting the presence of mercury in a specimen taken from the heart of a log of timber 10 inches by 5 inches and 9 feet long. He also details appearances of the destructive action of the corrosive sublimate upon the iron-work with which it came into contact, which would be prejudicial to the use of iron bolts in kyanized sleepers. A drawing, explanatory of the whole apparatus, accompanied the communication. In answer to questions relative to the process of exhausting the air from the receiver in which the bank-note paper was wetted at the Banks of England and Ireland previously to being printed, Mr. Oldham stated that as an experiment a packet of 1000 sheets of paper had remained a whole day in water without being wetted through whereas, by exhausting the air from the vessel containing them, to a partial vacuum of 22 inches of the barometer, and admitting water, they had been perfectly saturated in five minutes ; the edges of the paper in simple immersion, would rot away before the mass was saturated; by the exhausting process 5,000 sheets of bank-note paper would absorb 16 lbs. of water. Mr. Simpson conceived that exhaustion would facilitate the process of kyanizing; but he believed that if time was allowed pressure would accomplish the same end as perfectly, for he had observed that pieces of wood which had remained four or five days in a water-main, under pressure, had become perfectly saturated. Captain Scoresby, in his account of the whale-fishery, remarks, that when a whale carries a boat down, it rarely rises again, most probably because the fish plunges to such a depth that the extreme pressure water-logs the boat: instances had been known of the specific gravity of the planking being doubled by being carried down. Mr. Newton remarked, that immersion of timber in close tanks had been practised by Mr. Langton many years since, for bending timber a boiling fluid was used in the tanks, and the wood was subjected to heat for a considerable period. He had understood that Mr. Newmarch of Cheltenham, was the first person who used corrosive sublimate for preserving timber, and that he had prepared and employed considerable quantities of wood. Mr. Kyan subsequently revived the system. In Mr. Oldham's process of wetting paper, pressure was not requisite on account of its open texture. About the year 1819, Mr. Oldham had tried the same process with perfect success, for preserving meat. The Exhaustion had been tried by Mr. Harris, for cleansing wool. cops of wool were put into an exhausted receiver, a solution of an alkali was then admitted; after remaining a short time in the liquid, a sufficient quantity of diluted acid was added to neutralize the alkali, and the wool was washed out in clean water. The process succeeded perfectly, but was too expensive. Mr. Palmer had employed the kyanizing process for large pieces of timber, for the ribs of lock-gates, but had no means of ascertaining the depth to which the mercury had penetrated. The use of corrosive sublimate was first suggested by Sir H. Davy, in his lectures at the Royal Institution, as a means of destroying the vegetating process in timber, by the combination of the chlorine in the former, with the albumen of the latter. Mr. Palmer much doubted whether the means used for exhausting the capillary tubes, effected the object, unless the timber was in a dry state, and he considered it equally doubtful whether the solution could be forced to any considerable depth by compression, especially if any moisture actually filled the capillary tubes. The application of pressure in the process of salting meat, suggested by Mr. Perkins many years ago, was a complete failure. Mr. Simpson observed that, in the experiments of Messrs. Donkin and Bramah, pressure alone had been used, and it could easily be understood, that owing to the cellular formation of meat, the pressure, instead of forcing the salt through it, caused the substance to collapse, and the brine was prevented from penetrating. Mr. Braithwaite explained, that in Payne and Elmore's process, although pressure had been found indespensable, the meat was more perfectly prepared when exhaustion was also employed, therefore both were now combined. Mr. May reverted to the subject of kyanizing timber,―he believed that exhausting the air from the tanks, previously to the admission of the solution, was a loss of time-the fluid should be admitted first, or at least while the exhaustion was proceeding; labour and time would thus be saved, and the air would be more completely expelled from the capillary tubes, before pressure was applied. It was essential that the timber should be, as far as possible, deprived of its sap as well as dried; as either sap or moisture appeared to prevent the proper action of the corrosive sublimate. Mr. Cubitt regretted that experiments had not been made on the same kinds of wood, both with and without exhaustion. The experiments on small pieces of foreign (Memel and Dantzic) timber, with 80 lbs. to 100 lbs. pressure, without exhaustion, showed an increase of weight of from 1 to 2 oz., in pieces of about th part the size of a sleeper, and that result agreed very nearly with his practice with sleepers of Memel and Dantzic timber, when kyanized without exhaustion, under a pressure of 80 lbs. to the inch; sleepers of 2 to 2 cube feet, gaining from 3 lbs. to 5 lbs. in weight, by the process. No result had been given of experiments with sleepers of foreign fir timber, in which both exhaustion and pressure had been applied; but it appeared that the Scotch fir sleepers, weighing 100 lbs., when kyanized under exhaustion and a pressure of 100 lbs. to the inch, gained 33 per cent. in weight, which was equal to 3 gallons of water being forced into less than 3 cube feet of timber; he thought that this difference could not be all due to exhaustion, but that it must depend greatly upon the quality of the wood, because under a pressure of 100 lbs. to the inch, the air contained in a tubular substance (such as fir timber) would all be compressed into |