added that in order to ascertain from actual Mr. Walker. practice the value of the compound system, so far as the hydraulic pumping engine was concerned, he had taken the best example of the non-condensing engine made by Sir Rilliam Armstrong, V.-P. Inst. C.E., for Mr. Rarriaon, Past-President Inst.C.E., and it consumed, according to the indicator card, 35 lbs. of water per HP. per hour, while the compound engines made for the East and West India docks consumed little more than 12 lbs. Another matter to which he wished to call attention was the ingot crane. According to the ordinary way of making it, or where the lifting was done entirely by one ram, thc greater the margin of safety required for carrying the load at the end of jib, the greater the diameter of the ram, and it was obvious that a larger quantity of water would be consumed a t each stroke of the cranes. With the ordinary construction, where the ram was made of the diameter necessary for safety when carrying the load, the ram had much more power than was required ; and if a careless workman should put more on to the crane than it was intended to carry, or if the end of the crane should come in contact with the building, or, in the case of the Bessemer works, with the converter, the crane was sure to be broken. He had known serious accidents occur from this cause. With the arrangement he had described this danger was avoided. The centre ram might have any amount of margin for safety; it might be balanced and the side rams arranged to have a maximum lift, so that the workman could not lift more than was intended, and if the jib end should come in contact with any unforeseen object no danger would arise, as the crane would simply stop. Fig. 8 showed one of the nicest arrangements he had seen. It was not altogether his own ; it had been carried out in a workmanlike manner by Bfessrs. John Brown & Co., who were making some large ingots, and doing good work with little labour. The process of making steel, whether by the Bessemer or the Siemens method, having been invented, the success, not only in the quality but in the cost, largely depended upon the mechanical engineer. He might mention that fewer men were required in the manufacture of steel by these two processes than by refining and puddling. Figs. 11 and 12 exhibited the converters as successfully employed in Thomas and Gilchrist's process a t Middlesbrough. When the Paper was written these converters had not been tried, and it was determined to Downloaded by [] on [12/09/16].
