Hillside Greenhouses. 23 



ninety-three feet, covering about one-seventh of an acre. The glass slopes 

 at an angle of twenty-three degrees. 



The heating apparatus at the lower part is of the simplest character, 

 consisting of a square brick furnace, the top of the fireplace being formed 

 by a semicircular iron arch. The fireplace is provided with a damper, 

 which gives a direct or return draught, at pleasure. The smoke-flue is 

 formed of cement pipes, carried up under one of the walks, following the 

 slope of the house, and, about half-way up, carried outside the wall to a 

 short upright chimney of the same materials. Above the fireplace, the 

 brickwork is carried up so as to form a hot-air chamber ; and from this, 

 two hot-air flues slope up, and terminate at about half the distance up (or 

 across) the house. At the same height as the termination of the hot-air 

 flues commences a cold-air flue, which takes the cold air to the furnace at 

 the bottom of the house. 



Provision for watering is made by a cistern above the house, from which 

 pipes are led, having a stopcock at each of the upper sections, from the 

 last of which a hose conducts the water over the remaining part, so that 

 the whole house can be showered in fifteen or twenty minutes. 



The first and greatest advantage of this method of building is the equal 

 diffusion of the heat in all parts of the house ; several thermometers placed 

 in different parts indicating no greater difference than two degrees between 

 the warmest and coolest parts. This equable heat has hitherto been 

 attained only by means of expensive hot-water heating apparatus, and even 

 then less perfectly than by the cheap and simple hot-air furnace described 

 above. 



The second point gained is the saving in fuel ; only thirteen tons of coal 

 having been put into this house in autumn, and a part of this having been 

 left over in spring : while a house of the same area with this, of ordinary con- 

 struction, and with such heating apparatus as is commonly used, will con- 

 sume about five times this quantity. It will be seen at once, that, besides 

 the economy in the coal-bill, the saving of labor in handling such a quan- 

 tity of coal is a not unimportant item'. 



Another advantage, which Mr. Strong deems very great, is, that no light 

 is lost in the front of the houses ; this part being generally deemed, in 

 houses of the common construction, of but little value : but here the ravs 



