504 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



tirely impossible to realize upon a large scale. In Penaud's 

 opinion the aeroplanes are our only hope. 



THE ADHESION OF LOCOMOTIVES TO RAILWAY TRACKS. 



M. Moschelle, engineer-in-chief of the district railway of 

 the Jura, states that ordinarily, after having determined the 

 total tractive force which can be produced by the adhesion 

 of any given locomotive to the rails of the track, engineers 

 deduct therefrom a certain proportion as being required for 

 the locomotive itself, and treat the remainder only as avail- 

 able for overcoming the resistance of the tender and other 

 parts of the train. He, however, is of the opinion that en- 

 gineers make this deduction on the erroneous assumption 

 that the friction between the wheels and the rails has to 

 overcome the resistance of all the moving parts of the en- 

 gine, while he maintains, on the other hand, that it is the 

 steam which overcomes this resistance, the adhesion of the 

 engine not being called upon at all. He further directs at- 

 tention to the fact that, by coupling a second pair of wheels 

 to the locomotive, so as to turn them into drivers, not only 

 is the adhesion available for traction increased by the effect 

 of the weight upon the other pair of driving-wheels thus 

 brought into play, but that the adhesion formerly enrployed 

 to overcome the journal friction of these wheels is no longer 

 necessary. Proceedings of Institution of Civil Engineers, 

 XXXIX., 347. 



NEW ADAPTATION OF SCREW PROPULSION. 



Rear -admiral Paynter, of the British Navy, has recently 

 presented to the Royal United Service Institution his views 

 concerning a new adaptation of screw propulsion to naval 

 vessels, concerning the merits and advantages of which his 

 own experiments, as well as the opinions of all who have con- 

 sidered it, seem to be highly favorable. The idea was first 

 suggested by Mr. J. Buchanan, who took out a patent for 

 certain features of his model. Several of the engineers and 

 large ship -builders of Great Britain having expressed to 

 Admiral Paynter their high opinion of Mr. Buchanan's ideas, 

 he states that he has felt himself justified in presenting the 

 matter as an important one to the attention of navigators 

 and ship -builders. The main feature of the improvement 



