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MARINE REVIEW. tt Independent Air Pumps of the U. S. Cruiser Columbia. The accomp#nying engraving showing independent vertical air pumps of the United States cruiser Columbia will no doubt be interesting to many readers of the REVIEW, as attention has been called in previous issues to this cruiser and the remarkable speed she made on her sea trial. The air pump is of the well known Blake type, having vertical double-acting steam cylinders and vertical single-acting air cylinders. This arrangement has the advantages of minimum floor space and weight, which are very important features for sea- going vessels of al] kinds, particularly for naval cruisers. These pumps are of the same pattern as those 1urnished the United Staves armored cruiser New York and the battleships Indiana and Massachusetts. The cruiser Minneapo- lis, a sistership to the Columbia, will also be provided with similar air pumps. On the trial trips of the Columbia and the New York, these air pumps showed the remarkable economy of less than one-quarter of 1 per cent. of the indicated horse power of the main engines, a result rarely, if ever, obtained before with any type of air pump, whether independent or connected. This high efficien- cy is obtained principally by the use of a perfected system of valve gear for ir F cf We, Ue | i HH re = ne BS _ ae ees i 2, BU asf i elle oir UI the steam cylinders, which controls the operation of the pump so perfectly that very few strokes or displacements are necessary to do a given amcuut of work. For instance, the average rate of speed of the air pumps on the trial trip of the Columbia did not exceed sixteen double strokes per minute when preduc- ing a first class working vecuum. The indicator diagram from one of the _ air cylinders, which also appears with this article, is almost an ideal card, both in vacuum forming qualities and in smoothness of action. This card also shows a remarkable amount of work done for each displacement. This air pump has two double-acting steam cylinders, each 16 inches diameter by 21 inches stroke, and two single-acting air cylinders, each 315 inches diameter by 21 inches stroke. Each air cylinder is provided with usual foot, bucket and head valves. A large round hand-hole plate in each air barrel admits of ready access to bucket and foot valves. Convenient hand-hole plates are also provided for the head valves, as also for cleaning out the casting that forms the base or suction box of the pump. The air cylinders and all their working parts are made entirely of composition, which is the usual practice in constructing such machinery for the United States navy. The piston rods of steam cylinders are of steel, as are also all of the working parts such as the walking beams, links, valve gear, etc. The valve gear is arranged so that the stroke can b- readily adjusted, even while the pump is in operation, so that the pump can make a full and complete stroke at any speed desired. This feature adds very much to economy in steam used. The Wm. Cramp & Sons Ship and Engine Building Company were so well pleased with both of these air pumps that they have decided to use them on the cruiser Brooklyn and the battleship Iowa, for which they were recently awarded contracts. The Geo. F. Blake Manufacturing Company have also Scale = 10 ths. Vae.. 25 A1ns. = supplied the vertical feed pumps, fire pump and bilge pumps, in fact the com- plete outfit of pumps, for all of the above named vessels, and also for the cruisers Marblehesd, Montgomery, Detroit, Chicago, Boston and Atlanta ; gunboats Dolphin, Machias and Castine ; battleship Maine ; monitors Puritan and Miantonomah ; ram Katahdin, and the dynamite cruiser Vesuvius. Large Sailing Vessels. 'There are few sailing vessels that can carry 5,000 tons of cargo, and nearly all of them are in the California wheat trade,' says the Boston Commer- cial Bulletin. "In eleven years sixteen 5,000-ton cargoes have been cleared from San Francisco in twelve vessels. One of these was a steamer and the other eleven were the ships Rappahannock and Shenandoah, built by Arthur Sewall, at Bath, Me., and the British ships Liverpool, Alice A. Leigh, Pal- grave, California. Lord Temp! mar-, Milton Stuart, Drumrock, Horensfeld and Manchester. The Rippahanneck was lost n 189%, and the Shenandoah is now making her third vovage, the Palgrave and California having each sailed twice, The other American ships that carry 5,000 tons are the Sewall ships Roanoke and Susquehanna, they with the Rappahannock and Shenandoah forming the famous 'big four,' which marked the end of wooden ship building at the Sewall yards." Signaling Devices. Robert Ernschaw of Chicago is the inventor of an electric bell system of signals between pilot house and engine room, that is thus described by a trade journal of that city: There is a simultaneous display of signals to both sender and receiver. The unique feature of the mechanism is the automatic "set back," that is, after a signal is given and registered, the giving of the next signal first throws back the register of the former one before the new signal is displayed. The device could a so be applied to elevators, etc., with advantage. The inventor is perfecting another device that will print in a fire and water proof box all signals to the engineer with the time, date and rate of speed at- tached, so if the vessel sinks, and the box can be secured, it will be positive evidence as to the fault causing the accident. Trade Notes, Parties likely to be interested in an automatic line-holding device should corresp nd with E. C. Akers & Bros., Port Huron, Mich. A 20-p+ge pocket brochure telling about the Metropolitan injector hag been issued by the Hayden & Derby ManufaciuringCompany,111 Liberty street, New York. A large number of the latest lake steamers are equipped with these injectors, and they are giving satisfaction. Send for a copy of the pam- | phlet, and see how this injector is constructed. J. L. Alberger, who is known on the lakes in connection with the manu- facture and sale of pumps and condensers, has patented and is manufacturing a live steam feed water purifier, which should be examined by lake engineers. He islocated at Buffalo and has taken his son into a partnership. A catalogue descriptive of the new machine will be mailed to anyone applying for it. Handy is the word that best describes the catalogue issued by Jenkins Bros., No. 71 John s'reet, New York. It shows to advantage their valves in great variety. Do you know that their iron body valves have been improved as well as their discs and standard packing? This company was well repre- sented by Charles W. Martin, Jr., at the national meeting of the Marine Engi- neers' Beneficial. Association in Washington recently. Reports of the number and capacity of pig iron furnaces in blast throughout the country on the rst inst., as well as stocks sold and unsold on the same date, show practically no change in the condition of this important branch of the iron industry dur- ing the month. The reports are in fact a repetition of the figures that have ruled for several months, showing light production and little inc:ease or decrease in stocks. It is generally ex- pected, however, that as a result of some improvement in fin- ished lines the furnace business will change somewhat for the better during the present month.