CAOUTCHOUC 



709 



The advantages are stated to be, less first cost than steel ; less -weight, 6 cwt. being 

 saved in each carriage by their use ; and great durability. 



Coleman's improvement consists in the use of iron rings to confine the lateral 

 swellings of India-rubber cylinders. (See fig. 411). They are used as bearing-springs 



411 



for engines and tenders on the North-Western Kailway, by J. E. M'Connell, Esq., who 

 prefers them to steel, as being easy in action, durable, safe, and easy of repair ; they 

 are used alto as buffer- and draw-springs. 



The next form of these springs is the invention of E. Eaton (see Jig. 412). This 

 spring seems to be peculiarly adapted to use where a powerful spring, acting through 



412 



a small space, and taking little room, is required, as for use in mining ropes and chains, 

 &c. Eaton's main idea is the use of laminae of India-rubber, of a maximum thickness 

 of -J an inch, with dividing plates, as in Lacey's and Fuller's, which avoids the objec- 

 tions stated above, by supporting the India-rubber at smaller intervals ; for springs, 



413 



where great power is wanted in little compass, and to act through short distances, 

 as in engine bearing-springs, lifting-springs, and some kinds of draw-springs this form 

 proves to be well suited. 



