42 THE CULTURE OP THE GRAPE. 



POLMAISE SYSTEM ATTACHED TO A FUEKACE ALKEAUT 

 CUNSTEUCTED. 



1 have had attached to a' furnace: already constructed, 

 (and that has been some time in use,) of dimensions 

 similar to the one described, a system of circulation ot 

 the air vvhich has proved very successful. It is very sim- 

 ple. The furnace has been enclosed, on the three sides 

 within the house, with brick work, leaving two or three 

 inches of space only for the hot-air chamber on all sides, 

 and this brick enclosm-e is continued along the sides of 

 the flue, (where the heat is great,) for about ten feet. 

 The whole of this brick work is then covered with stones, 

 placed two inches above the furnace, and the heat is led 

 into any part of the house by a brick flue, covered on 

 the top with stones and closed at the ends, with two 

 openings near the extremity for the hot air to flow out 

 on each side. An opening is left, about three inches 

 square, on the level of the floor on each side in the brick 

 work that surrounds the furnace, close to the back wall 

 of the house, to admit the cold air, which commences to 

 rush in as soon as the furnace and flue become warmed ; 

 and this circulation continues for hours after the fire has 

 burnt out, the brick work retaining the heat a great 

 length of time. The cost of this apparatus was about 

 twenty-five dollars additional. 



