164 Steam-Engine — Physics, ^t. 



on bearings. This axis {i i) may be of any length ; may ter- 

 minate in a crank or cog-wheel, or another cylinder (as here 

 represented) may be attached thereto at right angles to the 

 first, to co-operate and produce, at every moment, equal 

 power. 



Plate II. Fig. 6. Profile of the above, a a, the boiler ; 



c, valve ■, d e g, cylinder and frame ; /, valve ^ h h, cog- 

 wheels ; i, cog-wheels to move the pumps ; k k, condensers ; 

 m m, coverings in ; o c, gas-fire flue. 



Fig. 1. a, steam-pipe ; b, escape-pipe j c, fixed valve ; 



d, moving valve ; e, axis ; /, a washer ; g, section of frame ; 

 h, a washer ; i, centre-piece ; I I, steam-pipe ;kk, springs to 

 keep the valves together. 



The canal-boat has her wheel in the stern. (See Plate IV.) 

 The motion is given by a cog-wheel upon its axis (g) played 

 upon by another, upon a shaft, at right angles, to which the 

 engine communicates motion. The wheel being divided by a 

 space of two or three inches, into two parts, to allow room 

 for this shaft, and for the support of its end. 



Fig. 3, represents the arrangement of the machinery, occu- 

 pying the after-part, of the boat. An engine of twenty horse 

 power may thus occupy half a canal-boat, can tow a number 

 of others at such rate as may be proper on canals.* b b, the 

 boilers ; c, tar- vessel ; d, the cylinder ; / water-wheel. 



The supply of water to the boilers is either by a pump, in 

 usual form, or by the supply -chamber of my invention, (Plate 

 III. Fig. 2.) which consists simply of a pipe having two stop- 

 cocks, one end in a reservoir, the other opening into the 

 boiler at top, sloping downward for a foot or two. The cocks 

 are in the sloping point. The operation commences, by 

 opening the cock nearest the boiler, the steam drives the air 

 out of the pipe through the water into the reservoir ; shut 

 the cock, and the water rises from the reservoir to fill it ; 



* But it is not necessary (as in (he plate) to crowd the engine into the after- 

 part of the boat, the boilers maybe placed forward, and near them, or over 

 them, the cylinder, &c. The power is then communicated to the stern-wlieel by a 

 long, shaft, supported On, or immediately under, the deck. This arrangement 

 <;ives room for loading both behind and before the boilers and engine, andequalize? 

 ihe burden. This is the actual arrangement of the Merrimack boat. 



