WARMING AND VENTILATION. 311 



To avoid tbis serious trouble, it is necessary, by means of proper 

 arrangements, which should also be simple, to produce a regular and 

 almost constant motion of air from the apartments or the halls toward 

 these places, discharging from them to the exterior. This may be 

 accomplished in several ways. 



104. Court-yards of dioelling houses. — Apartment-houses, especially in 

 Paris, very often contain little yards, belonging to the stores on the 

 ground floor, which seriously affect the healthfulness of the upper stories. 

 Provision-stores, restaurants, dye-houses, drug-stores, «&c., give rise to 

 disagreeable or injurious smells, which rise and annoy the occupants of 

 the house and iujure the property. 



These disagreeable effects may easily be overcome in the following 

 way : The yard should be covered, in whole or in part, with a glass roof, 

 forming a single inclined x^lane between the ground-floor and the second 

 story. In an anglf, and at the upper part of this roof, should be placed 

 a chimney, extending above the upper cornice, the 'section of which 

 should be calculated so that with a velocity of about three feet a second 

 the air of the court-yard will be renewed once, or, better, twice an hour. 



At the lower part of this chimnej^ should be placed a gas-burner, con- 

 suming only 3i cubic feet an hour. The velocity being small and the 

 chimney high, about 1,800 or 2,000 cubic feet of air may be carried off 

 in an hour by this chimney to every cubic foot of gas burned, and thus 

 a constant purification of the yards be secured. 



When local arrangements favor, it will only be necessary, in order to 

 keep up the draught, to carry a smoke-pipe up the chimney, or to start a 

 fire in a coke-stove placed in it. 



105. Kitchens. — When ranges with hot-air passages, such as are now 

 in general use, are employed, it will be easy when they are put up to 

 place hot- water pipes around the grate, and carry them a certain distance 

 up the chimney and back to the range, as in the boilers of hot-water 

 heating-apparatus, which woukt secure a sufficient draught. 



lOG. Use of gashurners for the ventilation of kitchens — In kitchens 

 lighted by gas, when the ranges are already put up in the usual way, 

 lighting one or two gas-burners at the bottom of the chimney, to be 

 kept burning only while cooking is going on, would iu most cases suflice 

 to produce a draught sulficient to carry off' all smell. 



Example. — The kitchen for a single flat in Paris is considered quite 

 large if 10 feet long, 13 feet wide, and 11^ feet high ; that is, with a con- 

 tent of 1,490 cubic feet. 



It follows from direct experiment that, with the aid of a single gas- 

 burner, consuming 1^ feet an hour, and kept burning only while the 

 meals are being prepared, that is to say, at most six hours a day, there 

 may be produced every hour, with sheet-iron ventilating-pipes Oi inches 

 iu diameter, and 



52 39 33 20 feet high, 



the renewal of 1,780 1,475 1,407 1,257 cubic feet, 



