Thee^mostat-thermosiphon ( "section) A. Firegrrate. B. Vent-holes, through 

 which the hiiioke parses to j;o out at D. C. The bars. D. Opening for al- 

 lowing the escape of gas in combustion. E. Openings serving to excite the 

 draft when the apparatus is lighted. E. The chimney. 



(^Front Elevation). At the foot, the ashpan; above the door of the fireplace; 

 above, on the left, the two pipes for the circulation of the water, that above 

 for the flow, that below for the return. 



or workshop, which gardeners call a 'tambour;' we shall 

 always advise to place the apparatus in the place which pre- 

 cedes the house, and content ourselves with the pipes for heat- 

 ing the house or houses, because the same apparatus is capable 

 of heating several during the severe cold. The smallest appa- 

 ratus could easily heat 100 metres of pipes. Some dissatisfied 

 minds object that this apparatus does not contain sufficient 

 water about the fireplace, because, up to the present time, 

 they have seen enormous boilers, and they think it is the size 

 that gives power. Experiment has demonstrated that a huge 

 quantity of water about the firegrate is useless, and that with 

 a less volume of water a circulation is better kept up, because 



