38 ANNUAL OF SCIENTIFIC DISCOVERT. 



claimed that the same amount of steam in such an engine will 

 accomplish more than in one of the ordinary kinds." Van Nos- 

 trand^s Eng. Mag. 



RAILWAY AXLES. 



In a letter to the " Times" Sir Joseph TVhitworth makes a sug- 

 gestion relative to the construction of railway axles, which is 

 deserving of attention by the engineers of railways. He proposes 

 that a hole should be drilled through the centre of the axle, 

 throughout its length, thus opening up to inspection and exami- 

 nation that part of the material which, in the case of ordinary 

 manufacture, is most subject to unsoundness. The hole should 

 be about an inch in diameter, and, with suitable mechanical ar- 

 rangements, might be drilled at an average cost of about Is. 

 6d., per axle. With the outside turned and the inside thus 

 exposed to view, a serious flaw in an axle, which is only about 

 4^ inches in diameter, could hardly escape discovery. The plan, 

 he says, would also diminish the tendency of the axle to get 

 heated, and, by renewing the material near the neutral axis, 

 would, under the circumstances, reduce the internal strains, and 

 render the axle safer. Van Nostrand's Eny. Mag., Oct., 1870. 



PUMPING ENGINES. 



A set of the largest pumping engines yet made have just been 

 completed by Messrs. Gyime & Co., of the Essex Street Works, 

 Strand; they are to be erected in Denmark for some heavy 

 drainage works, to reclaim 20,000 acres of land for the jSIissum 

 Fjird Company, and of the most approved construction. The 

 manufacturers are confident that the engines and pumps will 

 raise 40,000 gallons, 178k tons, 12 feet high in one minute, which is 

 nearly 50 per cent, more than contracted for. The machinery 

 consists of a pair of engines, 4 feet apart from centre to centre, 

 coupled, with a pump on each side. The engines are 21 inches 

 cylinder expansive condensing, 21 inches' stroke, mahogany lagged, 

 running at 140 revolutions (490 feet piston speed) per minute, 

 and consuming 3 pounds per horse-power per hour; vacuum 27 

 inches. The pumps are constructed on Messrs. Gynne & Co.'s well- 

 known centrifugal principle, and are 42 inches' diameter in the 

 pipes. The same manufacturers will shortly have completed a 

 combined pumping engine for the Punjaub Railway, to discharge 

 1000 gallons per minute 60 feet high. Van Nostran&s Eng. 

 Mag. 



* 



ELASTIC TIRES FOR TRACTION ENGINES. 



" Engineering" states that an interesting trial was recently car- 

 ried out between Rochester and Chatham of a 5-horse traction 

 engine constructed by Messrs. Aveling & Porter, of the former 

 place, and fitted with tires formed of India-rubber segments at- 

 tached to iron plates by a process patented by Messrs. L. Sterne 



