48 On the Ufc of Steaiti 



liquids, and for keeping them hot, in a variety of cafes, m 

 which lire, applied immediately to the bottoms of the con- 

 taining vefiels, is now ui'^d. 



In dyeing, for inftance, and in brewing, and in the pro- 

 ceffes of many other arts and manufactures, the adoption 

 of this method of applying heat would be attended, not only 

 with a great faving of labour and of fuel, but alio of a confi- 

 QJerable laving of expenfe in the purehafe and repairs of boil- 

 ers, and of other expenfive machinery : for, when (team is 

 ufed inftead of fire for heating their contents, boilers may be 

 made extremely thin and light; and, as they may eafily be 

 fupported and ftrengthened by hoops and braces of iron, and 

 other cheap materials, they will coil but little, and feldom 

 ftand in need of repairs. To thefe advantages we may add 

 others of (till greater importance : boilers intended to be 

 heated in this manner may, without the fmalleft difficulty, be 

 placed in any part of a room at any diftance from the lire, 

 and in fituations in which they may be approached freely on 

 every fide. They may, moreover, eafily be fo furrounded 

 with wood, or with other cheap fubJtances which form warm 

 covering, as mo ft completely to confine the heat within them, 

 and prevent its efcape. The tubes, by which the fteam is 

 brought from the principal boiler, (which tubes may conve- 

 niently be fufpended juft below the ceiling of the room,) 

 mav, in like manner, be covered fo as almoft entirely to pre- 

 vent all lofs of heat by the furfaces of them ; and this to 

 whatever dillances they may be made to extend. 



In fulpending thefe fteam-tubes, care mult, however, be 

 taken to lay them in a filuation not fierfeSlly horizontal under 

 the ceiling, but to incline them at a finall angle, making 

 them rife gradually from their junction with the top of a 

 lar.sre vertical fteam- tube, connecting them with the fteam- 

 boUer, quite to their fart heft extremities: for, when thefe 

 tubes are fo placed, it is evident that all the water formed in 

 them, in confequence of the condensation of the fteam in its 

 patfage through them, will run backwards and fall into the 

 boiler, inftead of accumulating in them, and obftrucling the 

 pafTage of the fteam, which it would not fail to do were there 

 any confiderable bends or waving,-., upwards and downwards, 

 in thefe tubes, or of running forward and defcending with 

 the fteam into the vellels containing the liquids to be heated, 

 which would happen if thefe tubes inclined downwards in- 

 ftead of inclining upwards as they recede from the boiler. 



In order that clear and diflinct ideas may be formed of the 

 various parts of this apparatus, even without figures, I fhall 

 diitinguifh each part by a fpecific name. The veifel in which 



water 



