Trials of Traction- Engines at Wolverhampton. 551 
out as may bo required in turning sliarp curves. The driviiig-wlicels are 
5 feet diameter over tlie indiarubber, are made of wrought-irou discs, and a 
wrought-iron flanged rim, containing bctweeu the flanges indiarubber tyres 1 foot 
Fig. 12. — Indicator Diagram of ihe forward cylinder of Messrs. Ttansomes^ 
Sims, and Head's S-Horsc-imccr Farm Steamer, No. 2149. 
Fig. 13. — Indicator Diagram of the after cylinder of Messrs. Banscmes, 
Sims, and Head's 8-Horse-jpower Farm, Steamer, No. 2149. 
