EXPLANATION OF THE PLATES. 399 



Diameter of Cylinder, in inches. Diameter of Piston-rod in inches. 



7 . . 1-04 



8 . . 1.2 



9 . . 1-34 



10 . . 1-5 



11 . . 1-64 



12 . . 1-8 



13 . . 1-94 



14 . . 2-1 

 16 . . 2-375 



For more detailed information on this important subject, see description of Plates 

 LXXXIX XCII. 



PLATE LXVIII. 



This Plate represents a plan and section of boiler seating, for a twenty horse en- 

 gine, at the manufactory of Messrs. Whitworth and Co., Manchester. 



PLATE LXIX. 



This Plate represents Messrs. Hague's double acting cylinder, with slides, &c. 



Fig. 1 is the cylinder, showing the facings for slide ; A is the passage to the top ; 

 B the passage to the bottom ; and C the exhausting passage. 



Fig. 2 is a section of the cylinder and slide in the position for letting in the steam 

 at the top A, and exhausting at the bottom through B C ; D is the slide with the 

 exhausting passage through it ; F is a spring to keep the slide to its face ; and G 

 the steam pipe from the boilers. 



Fig. 3 shows the facings of the slide. 



Fig. 4 shows the side of ditto. 



