420 



SCIENCE. 



IVoL. II., No. 34. 



tion between the plates. It is obvious, that, 

 were the plates to firmlj' adhere together, the 

 strength of the spring would either be verj- 

 largelj' iuercased, or the same strength might 

 be attained b3' 

 the use of a 

 less number of 

 plates ; and the 

 latter course 

 has Ijeen car- 

 ried to its limit 

 by the patentee 

 of the Cliff 



spring. A elliptic' 



spring made of 



one plate must be of good steel, as, when 

 loaded, the difference in the alteration of the 

 lengths of its upper and lower surfaces is 

 considerable, demanding a highly elastic steel. 

 In the spring we illustrate, four springs are 

 arranged side by side, — a plan which unites 

 the advantages of a plate spring and a solid 

 spring. Should one spring break, the other 

 three will probably carry the load, while four 

 springs side by side weigh no more than a 

 spring of the same total strength, composed 

 of a single bar of the same thickness, but of 

 four times the width. A set of these springs 

 for a passenger-car weighs nine hundred and 

 twenty-eight pounds, while a set of the Penn- 

 sylvania railroad standard springs for the same 

 purpose weighs sixteen hundred and thirty- 

 two pounds, a difference of seven hundred 

 and four pounds in favor of the solid spring. 

 These springs have been lately introduced, 

 and are being tried on the Boston and Albany 

 and other railways.. The diflBculties of tem- 

 pering and making a spring of one solid bar 

 are considerable- but it is to be hoped they 

 may be surmounted,- as the weight of cars is a 

 serious evil, " which has increased, is increas- 

 ing, and ought to be diminished." 



Mr. S. P. Tallman of New York exhibits a 

 safety-drawbar for cars. Two pieces of timber 

 are bolted between the middle sills of a ear, 

 and others are bolted to the under side of these 

 timbers and the middle sills, forming a solid 

 mass of timber, which 

 receives both the buff- 

 ing and drawing strains, 

 the drawbar running 

 through the timber, and 

 being provided with 

 springs at both ends. 

 The spring nearest the draw-head takes the 

 buffiug-strain, and the spring at the end of 

 the drawbar serves as a draw-spring. The 

 disposition of the timbers enables them to be 



secured b3' more than the usual number of 

 bolts, and the arrangement appears to be 

 strong and simple, and not so liable to fail- 

 ure as the ordinary' draught timber. 



Numerous 

 refrigerator- 

 cars were ex- 

 hibited ; and 

 doubtless im- 

 provements 

 will be much 

 facilitated b y 

 the opportuni- 

 ties thus given 

 to secure infor- 

 mation, though it is to be regretted that the 

 management of the exposition did not take 

 steps to secure an eflicient competitive trial 

 of the cars under practical conditions. Beer, 

 fruit, vegetables, etc., might have been placed 

 in the cars, and locked up for a few days, 

 when a careful examination of the contents 

 would have given some indication of the rela- 

 tive merits of the cars. 



The use of continuous brakes on passenger- 

 trains has been found to be so advantageous, 

 that their adoption on freight-trains is merel}' 

 a question of time. Several forms of continu- 

 ous Ijralves, applicable to freight-trains, were 

 exhibited; the Weslinghouse brake companj- 

 showing a cheaper form of their well-known 

 automatic brake, the reservoir being made of 

 cast iron, and bolted to the C3'linder. The triple 

 valve, however, and other parts, differ little, ex- 

 cept in size, from the brake used on passenger 

 equipment. A cheaper form of brake, which 

 requires no special pump or other fittings on 

 the engine, or even a continuous brake con- 

 nection through the train, is operated by the 

 action of the ordinary hand-brake on the ten- 

 der. The consequent compression of the draw- 

 heads in the train is made b^' the peculiar 

 mechanism of this, brake -gear to apply the 

 brake-shoes to the wheels of the cars. 



This form of brake is peculiarl}- applicable 

 to freight-service, as it allows of cars not fitted 

 with the brake being run in the train without 

 interfering with the use 

 of the brake on the cars 

 equipped. This class 

 of brake can hardlj- be 

 termed 'automatic' in 

 p„vK. the fullest sense of the 



term, insomuch as it 

 does not work, should the train part in two. 

 On the other hand, failure on any one car 

 cannot impair the efficiencv of the brake on 

 the rest of the train. 



m 



