16G Steam-Engine— Physics, ^c. 



as well as to the coal-fire below, where the gas and tar are 

 ignited. The fireman judges of the proportion of each, by 

 the effect ; the object being to produce a nearly white flame 

 without appearance of tar. Thus flame is appUed to the 

 greatest possible surface, and the apparatus adds very little to 

 the cost of the engine. 



There are also two improvements in the boiler, which I 

 deem it important to mention. First, the lining or covering 

 of the flue within with sheet-iron or copper, perforated with 

 small holes, reaching down its sides, nearly to the bdttom. 

 Plate III. Fig. 2. a the boiler ; b the flue; d the grate; 

 c c the lining. 



This causes the water to circulate rapidly between them ta 

 the top of the flue, and protects it from being run dry, or 

 heated red hot, when the water gets, by accident, too low. 

 The lining also causes the steam to form much faster, in conse- 

 quence of this circulation. 



The other is the interior boiler. A vessel occupying the 

 back part of the flue. Plate II. Fig. 8. {d) communicating 

 downwards with the water, and upwards with the steam of the 

 main boiler. The fire acts upon it very forcibly, surrounding 

 it on all sides. 



I have said there is no reciprocating movement in Morey's 

 engine. Should it be objected that the piston moves in the 

 cylinder as usual, it must be apparent that it also moves cir- 

 cularly ; it is in fact the cylinder that moves, carrying the 

 piston with it, which gives and keeps up the motion, by 

 drawing and pressing on the centre-piece, and communicating 

 the resistance thence to the guides of the cross-piece on the 

 insides of the frame, which thus receives its motion. 



In fact, this form of the engine seems divested of all the 

 usual drawbacks on its power, and leaves it to act freely with 

 any velocity, according to the strength of the steam in the 

 boilers. 



Such it appears in principle, and such thus far in practise. 

 I have therefore preferred it for the purposes of navigation, 

 and have purchased the patent right. But, though interested 

 to rpcommend it. I cannot expect it to be preferred by the 



