20 Heating by hoi Water and Steam combined. 



end, and descended to the bottom, along which it continued 

 for 3 ft. Part of the pipe at the bottom of the cistern was 

 perforated, and the end was open for the steam to pass into 

 the water ; and a pipe was fixed to the level of the water, 

 which conveyed the waste water and steam to the outside ot 

 the house. The water in the cistern was boiled by this ap- 

 paratus in about 30 minutes, and retained a considerable heat 

 for two days. This plan has also been adopted on a larger scale 

 by my present employers, Messrs. T. and J. Backhouse. The 

 three cisterns in three of their houses are built with brick 

 and Roman cement, and are 24 ft. long, 1 ft. 10 in. wide, and 

 2 ft. 9. in. deep, and are all heated by one boiler, the flue to 

 which is continued through the houses, and gives out a con- 

 siderable quantity of heat. When these cisterns are once 

 heated, they retain the heat for several days ; but tiieir 

 length and depth are perhaps greater than is of advantage, as 

 it takes three or four hours to heat each of them. The 

 steam can be turned into one cistern at a time, by means 

 of stopcocks in the branch pipes which convey it from the 

 main pipe ; and the main pipe lies under a trellised footpath 

 through the houses. There is a communication, by means of 

 pieces of lead pipe at the level of the water, between these 

 three hot water cisterns, by which means the waste wat^r is 

 carried into the one nearest the cistern whence the boiler 

 is supplied by a pump. It is conveyed into this last cistern 

 by means of a pipe, which passes from near the top of the 

 hot water cistern, down the side, and under ground a few 

 feet. The pipes for carrying off the steam come thi'ough 

 the wall to the outside, and they are found to answer best to 

 open directly forward, for, when turned up, snow is apt to 

 fi'eeze upon them, and close them, when not at work. In 

 order to secure the hot water cisterns from explosion, in case 

 of these waste steam-pipes getting stopped, a piece of copper 

 pipe passes through the cover of each cistern down to within 

 a few inches of the bottom. It is probable that cisterns of 

 sheet-iron or other metal would answer better than of stone 

 or brick, as they would give out heat more readily, and be 

 less difficult to keep watertight. Where the main pipes have 

 to descend, as is the case here, it is necessary to fix a cock to 

 the lowest part, in order to draw off the condensed water 

 that remains in the pipes after using ; but the best plan, where 

 it can be adopted, is for the boiler to be set so low that 

 the steam has to rise to the cisterns ; consequently the con- 

 densed water from the pipes will return into the boiler. 



I am, Sir, &c. 

 York Nursery^ Dec. 4. 1827. Henry Bains. 



