SIX) 



[ 853 ] 



STO 



feet long, thirteen feet broad, seven 

 feet high in the centre, and four feet 

 high at the two fronts, having a super- 

 ficial surface of glass amounting to 588 

 square feet, Mr. Eendle has a tank 

 eighty-three feet long, running round 

 three sides of the house, four feet wide 

 and about eight inches deep, and con- 

 sequently capable of containing nearly 

 -500 cubic feet of hot water, though 

 only half that quantity is used. This 

 is closely approaching to the size 

 pointed out, according to Mr. Tred- 

 gold's formula. The mean temperature 

 of a hot-water tank will never be much 

 above 100, so that for the sized house 

 mentioned by that skilful engineer, the 

 divisor must be 2.1 times the difference 

 between 100 and 60, which gives as 

 the quotient 335 cubic feet. 



The tank in Mr. Eendle's propagat- 

 ing house, is built lined with Koman 

 cement, and if the temperature at the 

 time of lighting the fire be 00, the 

 temperature of the atmosphere of the 

 house 07, and the temperature out-of- 

 doors 50, the quantity of small coal or 

 breeze required to raise the temperature 

 of the water to 125 U , is 28 pounds. In 

 twelve hours, the water cools after the 

 fire has been extinguished, from 125 

 to 93. 



When steam is employed, the space 

 for steam in the boiler is easily found 

 by multiplying the length of the pipe in 

 feet, by the quantity of steam in a foot 

 in length, of the pipe. 



Interior 



diameter of pipe 

 in inches. 



1 . 



H 

 2" . 



!* . 



4 

 5 

 6 



7 . 

 8 

 

 10 



Decimal parts of a 

 cubic foot of steam 

 in each foot of pipe. 

 . 0.0545 



0.1225 

 . 0.2185 



0.34 

 . 0.49 



0.873 

 . 1.063 



1.964 

 . 2.67 



3.49 

 . 4.42 



5.45 



In the above noticed house, the 

 length of pipe five inches in diameter, 

 is 150 feet; and these multiplied by 

 1.363=20.0 cubic feet of steam, and as 



the pipe will condense the steam .of 

 about one cubic foot and one-third of 

 water per hour, therefore the boiler 

 should be capable of evaporating 1-| 

 cubic feet of water per hour, to allow 

 for unavoidable loss. In the extreme 

 case of the thermometer being at zero, 

 the consumption of coals to keep up 

 this evaporation will be 12f pounds per 

 hour. 



These calculations are all founded 

 upon the supposition that the condensed 

 water is returned to the boiler whilst 

 hot; but if this cannot be effected, 

 then one-twelfth more fuel will be re- 

 quired. The boiler for the supply 

 either of steam or hot-water, should be 

 covered with the best available non- 

 conductor of heat, and this is either 

 charcoal or sand. 



A case of brickwork, with pulverised 

 charcoal, between this and the boiler, 

 is to be preferred to any other. A 

 boiler having a surface of seventy feet 

 exposed to the air, in a temperature of 

 32, requires an extra bushel of coals 

 to be consumed per day, to compensate 

 for the heat radiated and conducted 

 from that surface ; and the smaller the 

 boiler, the greater is the proportionate 

 waste. The surface of the pipes should 

 be painted black, because a surface of 

 this colour gives out more heat in a 

 given time than any other. 



Bark or Moist Stove. Mr. Loudon 

 gives the following design and descrip- 

 tion of a moist stove, wanned on the 

 old plan of deriving heat by the com- 

 bined agency of bark and flues. In- 

 stead of a stage in the centre it has a 

 pit, which may be from two-and-a-half 

 to four feet deep, according as bark or 

 leaves are to be used, the latter material 

 requiring the greatest depth. It is 

 commonly surrounded by a thin brick 



wall : but planks of stone, or plates of 

 slate Or cast-iron, are to be preferred. 



