68 



Bird - Lore 



vertical shafts back of exterior walls or in 

 attic, which heated (lighter) air is by gravity 

 forced up and out of protected slot opening 

 along the ridge pole of the roof, by and for 

 cooler (heavier) air rising from beneath the 

 bird-houses. This operation automatically 

 occurs and continues whenever and while the 

 temperature at any point inside of air-shafts 

 or attic is warmer than the air beneath the 

 bird-houses and irrespective of a dead calm 

 or breeze or wind. 



"The same principle is utilized in many 

 ways in live-stock, hog and poultry buildings, 

 the 'animal-heated air' automatically rising 

 and passing out ventilators in roof; in prune- 

 and other fruit-driers; in ventilating hotel 

 and restaurant kitchens; in warm-air fur- 

 naces; in the latest Rochester hand-lamps, 

 etc. the air in exhaust flues, hot-air pipes, 

 and chimneys heated from burning fuel, 

 lighter than cooler air beneath being auto- 

 matically forced out above. 



"Heated air rises vertically; it will not 

 move horizontally except by being forced by 

 wind or draft as natural forces, thus making 

 openings through walls at side or end only, 

 of other bird-houses, of little or no avail in a 

 dead calm or slight breeze (a very frequent 

 occurrence) to relieve the interior of the heat 

 of the sun. 



"Shielded from both storm and the sun's 

 rays by separate exterior walls and roof, and 

 also shielded from the sun's heat penetrating 

 same, by intervening ascending columns of 

 air in surrounding air-shafts etc., the tem- 

 perature of 'air-cooled shelter' nesting-boxes 

 and the air therein will remain the same as 

 that of the air beneath, and the interior of 

 nesting-boxes will be free from rain, sun's 



heat and cold drafts detrimental to hatching 

 and to young birds. 



"White or yellow paint on tops of roofs 

 and even on sides where there are no entrances 

 will reflect to some extent the heat rays from 

 the sun, and not be objectionable to the 

 birds. 



"Entrance extension on each side with 

 horizontal slot for passing of nest material 

 will speed the nest-building. 



"Wire sand screen of close mesh with hole 

 cut to fit snugly around entrance on inside of 

 exterior wall, and cut to fit snugly beneath 

 and at sides of entrance on outside, fastened 

 with screen staples, will remedy trouble 

 arising from smooth and slippery surfaces 

 around the entrance, and aid the birds in 

 passing in and out, and in fighting off from 

 the inside any marauding birds. 



"Shelter from the roasting heat of the sun 

 can be easily provided to quite an extent in 

 case of old-style bird-houses, as follows: 



"Installing an extra roof raised above the 

 original by furring strips >^ to i inch thick, 

 running from eves to ridgepole, leaving open 

 air-shafts between original and extra roof, 

 and an opening of i inch between roof-boards 

 at and along the ridgepole for exit of heated 

 air. Furring strips when placed should be 

 thoroughly painted in manner to exclude 

 moisture beneath them." 



Mr. Oilman is not in the business of 

 making bird-boxes for sale, and is very glad 

 to pass on his ideas to others. He writes that 

 he will be pleased to supply assistance to 

 anyone who may care to follow his plan. 

 For 25 cents each he will furnish 5x7 photo- 

 graphs showing (i)exterior, (2) interior, and 

 (3) complete description. 



