as a Vehicle for transporting Heat. 327 



these tubes inclined downwards, instead of inclining up- 

 wards, as they recede from the boiler. 



In order that clear and distinct ideas may be formed 

 of the various parts of this apparatus, even without 

 figures, I shall distinguish each part of it by a specific 

 name. The vessel in which water is boiled in order to 

 generate steam and which, in its construction, may be 

 made to resemble the boiler of a steam-engine I shall 

 call the steam-boiler; the vertical tube which, rising 

 up from the top of the boiler, conveys the steam into 

 the tubes (nearly horizontal) which are suspended from 

 the ceiling of the room, I shall call the steam-reservoir. 

 To the horizontal tubes I shall give the name of conduc- 

 tors of steam ; and to the (smaller) tubes which, de- 

 scending perpendicularly from these horizontal conductors, 

 convey the steam to the liquids which are to be heated, 

 I shall exclusively appropriate the appellation of steam- 

 tubes. 



The vessels in which the liquids that are to be heated 

 are put, I shall call the containing vessels. These vessels 

 may be made of any form ; and, in many cases, they 

 may, without any inconvenience, be constructed of wood, 

 or of other cheap materials, instead of being made of 

 costly metals, by which means a very heavy expense may 

 be avoided ; or they may be merely pits sunk in the 

 ground, and lined with stone or with bricks. 



Each steam-tube must descend perpendicularly from the 

 horizontal conductor with which it is connected, to the 

 level of the bottom of the containing vessel to which it 

 belongs ; and, moreover, must be furnished with a good 

 cock, perfectly steam-tight, which may best be placed 

 at the height of about six feet above the level of the 

 floor of the room. 



