404 EXPLANATION OF THE PLATES. 



object would be materially assisted by action of the chain HH, which in con- 

 sequence of the motion of the top of the bar A A A, would regulate the steam 

 valve so as to entirely close it in an extreme case. Fig. 2 shows the positions in 

 an extreme case, when by means of a switch, or pall, which lies upon the cross 

 bar, the parts are effectually prevented from returning to their original positions, 

 and the motion of the engine and train is soon brought to a stand. 



The same arrangement is fitted to the other side of the engine, and, as shown 

 in Figs. 2 and 3, cross chains are fixed from side to side, so as to connect the top 

 of each bar with the bottom of the other, and thereby insure the effect of the 

 brakes against all the four wheels, as shewn in Fig. 2. 



PLATES LXXIV. TO LXXXIII. 



The drawings contained in these plates relate to Mr. Morn ay's valuable paper 

 on " Paddle Wheels," inserted in the appendix, page 117, and their explanations are 

 to be found in that paper. 



PLATES LXXXIV. TO LXXXVIII. 



SIXTY-FIVE INCH CYLINDER ENGINE, ERECTED BY MESSRS. MAUDSLAY, SONS, 

 AND FIELD, AT CHELSEA WATER WORKS, 1837. 



The drawings in these Plates are as follow : 



Plate LXXXIV. Elevation of the engine pumps and air vessel. 



Plate LXXXV. Longitudinal section through the centre of the cylinder, nozles, 

 beam, main pump, &c. 



Plate LXXXVI. Fig. 1. Front elevation of the hand gear, levers, and rods, 

 with expansion tappet, &c. Fig. 2. Transverse section of nozles 

 through centre of valves. Fig. 3. Side elevation of the hand gear, 

 levers and rods, &c., &c. 



Plate LXXXVII. Longitudinal section through the centre of one of the boilers, 

 shewing the steam boxes, feed heads, floats, &c. 



Plate LXXXVIII. Fig. 1. Front elevation of the boilers, shewing the furnace doors, 

 steam boxes, damper pipes, feed heads, &c. Fig. 2. Transverse sec- 

 tion of the boilers, shewing the steam boxes, pipes and stop valves, 

 safety valves and pipes. 



