54 On the Ufe of Steam 



intended that they ihould be covered, and that coverings 

 would be provided for them. 



The vertical fleam-tubes, by which the fleam pafTes down 

 from the horizontal fleam conductors into the coppers, are 

 all conflructed of lead, and are from -J- of an inch to i l £ 

 inches in diameter ; being made larger or fmaller according 

 to the fizes of the coppers to which they belong. Thefe 

 fleam-tubes all pafs down on the outrides of their coppers, 

 and enter them horizontally at the level of their bottoms. 

 Each copper is furniilied with a brafs cock for letting off its 

 contents; and it is filled with water from a ciflern at a di- 

 ftance, which is brought to it by a leaden pipe. The coppers 

 are all furrounded bv thin circular brick walls, which lerve 

 not only to fupport the coppers, but alio to confine the heat. 



The rapidity with which thefe coppers may be heated, by 

 means of fleam, is truly aflonifhing. Mr. Gott a flu red me 

 that one of the largefl or them, containing upwards of 1800 

 gallons, when filled with cold water from the ciflern, requires 

 no more than half an hour to heat it till it actually boils ! 

 By the greatefl fire that could be made under fuch a copper, 

 with coals, it would hardly be poflible to make it boil in lefs 

 than an hour. 



It is eafy to perceive that the faving of time which will 

 sefult from the adoption of this new mode of applying heat 

 will be very great; and it is likewife evident that it may be 

 increafed, almofl without limitation, merely by augmenting 

 the diameter of the (leam-tube : care mud, however, be taken 

 that the boiler be fufficiently large to furnifli the quantities of 

 fleam required. The laving of fuel will alfo be very confi- 

 derabie : Mr. Gott informed me that, from the befl calcula- 

 tion he had been able to make, it would amount to near two- 

 thiids of the quantity formerly expended, when each copper 

 was- heated bv a feparate fire. 



But thefe favings are far from being the only advantages 

 that will be di ived from the introduction of thefe improve- 

 ments in the management of heat: there is one, of great 

 importance indeed, not yet mentioned, which alone would 

 be tufficient to recommend the very general adoption of them. 

 As the he.u communicated by fteam can never exceed the 

 mean temperature of boiling water by more than a very few 

 de ; ;cs, the fub fiances expofed to it can never be injured by 

 it. In many arts and manufactures this circumftance will 

 be prod . : e < great advantages, but in none will its utility 

 be more apparent than in cookery, and efpecialiy in public 

 kitchens, •■. 1 ere great quantities of food are prepared in large 

 boilers; for, when trie heat is conveyed in this manner, all 

 4 the 



