POULTRY KEEPING 553 



Regulator. Many are the methods that have been tried for auto- 

 matically regulating the temperature of the egg chamber. So far 

 all of them depend upon the principle of contraction and expansion. 

 The demand is for some simple device that will allow the tempera- 

 ture to rise so high and no higher, and that will maintain the tem- 

 perature at that degree regardless of the weather or external influ- 

 ences. Most regulators act upon a damper over the top of the lamp, 

 and, by opening or closing the same, regulate the amount of heat 

 that passes into the incubator. The expanding horseshoe-shaped 

 bar, the elliptical spring bar, and the metallic disk are the most com- 

 mon regulator powers of the present. Perhaps in the course of time 

 some one will make a regulator from a coil or spiral spring that, 

 reaching clear across the top of the egg chamber, will very accu- 

 rately control the admission of heat. 



At the present time the best regulator is the double disk, whether 

 filled with air or with liquid. Excellent results are obtained by using 

 the single disk, but the double disk is still better. The disk, in 

 order to be useful, should be large enough to have some force and to 

 note the slightest variation in temperature. A disk of only 1 or 2 

 inches diameter has hardly power enough, nor is it delicate enough 

 for quick and perfect action. The writer prefers the double disk 

 and that with a diameter of 4 or 5 inches. Such disks will be very 

 susceptible to changes in temperature and will be strong enough to 

 act upon the damper. Of course there are machines that use the 

 horseshoe or buggy spring expanding bar, which work fairly well; 

 but as fast as possible the writer has these attachments removed and 

 the disk substituted for them. Many purchasers have no patience 

 with a regulator that will not work from the start, and, owing to the 

 fact that first impressions are prejudicial, it is safer to ship articles 

 that will go together readily and work from the start. There is 

 something in the location of the regulator. The disk should be 

 placed near the center and well toward the back of the egg chamber. 

 It should be placed so high that it is not in the way of the eggs or 

 the tray. Another reason for placing the disk high is that, because 

 the chicks as they hatch will tumble around more or less before drop- 

 ping into the nursery { one or more of them may hit the regulator, 

 thus disturbing its adjustment and bringing disaster to the remain- 

 der of the hatch. The regulator should be strongly fixed in its 

 bearings, so that an accidental touch will not put it out of order. 



Most machines have the long bar or damper lever upon the top 

 of the body. This is a serious fault. The top of the machine is the 

 most convenient table for cooling, testing, or turning eggs, and it 

 should be free and clean for that use. Besides this, the lever, when 

 located outside and upon the top of the machine, is easily affected 

 by a current of air and also liable to become bent or dislocated. A 

 child, a stray fowl, a mouse, a cat, or a slight breeze will be likely to 

 interfere with the action of the regulator if it is exposed upon the top 

 of the incubator. Some makes of incubators have the damper lever 

 at the end of the case ; others have it above the egg chamber, where 

 it is covered and protected. The adjustment of the regulator should 



