68 



THE BOOK OF POULTRY. 



interested in the subject as far back as 1540. 

 In 1777, Dr. Bonnemain constructed his " Ec- 

 calobion," which actually supplied chickens to 

 the Paris markets, as well as to the Court, until 



all came to an end with the events 

 Early of 1814. Reaumur obtained fair 



Europe"'' "" ''csults from the heat of fermenting 



dung, heaped up round small casks, 

 and renewed as required. In 1845, M. Vallee, 

 poultry superintendent of the far - famed 

 Jardin des Plantes at Paris, constructed an in- 

 cubator which marks an epoch, containing as it 

 did a self-acting valve which opened to reduce 

 the temperature when too high. Its action 

 was crude and imperfect, but he thus introduced 

 a cardinal feature which is part of every in- 

 cubator at the present day. In or about 1846, 

 Cantelo introduced the supply of heat from 

 above. His apparatus hatched many chickens, 

 and was often exhibited, but was too costly 

 to come into general use ; and the same may 

 be said of the large and elaborate incubator 

 of Minasi, which was publicly exhibited in 

 England, and used by one or two purchasers, 

 so late as the publication in 1872 of the first 

 edition of this work. With these the older 

 group of machines may be said to come to a 

 close. 



There followed another school of experi- 

 menters, whose aim was to produce machines 



more generally useful, and acces- 



Pioneer sible, and portable. Carbonnier's 



Incubators. . ' ^ . , _ 



mcubator consisted merely 01 a 



rectangular tank of water heated, without flues, 



by a lamp placed in a chamber at one end. 



Under this was a drawer in which the eggs 



were placed, covered over by a canvas 



resting upon them, on which was borne half 



an inch of sawdust. In the tank was one 



thermometer, and in the drawer another, and 



the whole was regulated simply by incessant 



watchfulness. He laid down specifically that 



once a day the eggs were to be withdrawn, to 



be cooled for twenty minutes, then turned over, 



and the sawdust replaced upon them and 



sprinkled with tepid water. Many made this 



simple machine, and some hatched well 



with it, but the time and care needed were far 



too great. We have often wondered that a 



heating medium gently resting upon the eggs, 



like his layer of slightly damped sawdust spread 



upon a canvas, has not been more frequently 



attempted. 



Brindley's incubator, introduced in 1866, 



consisted of flues from a boiler circulating 



between an upper and lower pane of glass, 



which formed a radiating hot chamber, thus 



introducing another system much used since. 



Under this radiating chamber was a drawer 

 of felt, in which the eggs were placed. There 

 was a regulating valve, which let hot air out 

 from the chamber when required, but it did not 

 act very well, depending as it did upon the 

 expansion of mercury. This machine was 

 at one time used by several British fanciers 

 to do the final hatching-out of eggs pre- 

 viously incubated by hens. In 1865 Mr. F. 

 Schroder introduced for the first time a tank 

 of cold water under the eggs, whose evapo- 

 ration provided moisture, while the heat came 

 from a hot-water tank above. In 1866, Col. 

 Stuart Wortley introduced the principle of 

 warming a hot-air chamber by introducing a 

 greater or less length of water pipes always 

 kept boiling hot, and passed through stuffing- 

 boxes ; but this principle has never come into 

 use. It is rather remarkable that, although 

 Schroder's incubator was surrounded by cur- 

 tains, none of these machines were otherwise 

 provided with a case of non-conducting material, 

 so important for economy of fuel and uniformity 

 of temperature. 



Two other English incubators of the ex- 

 perimental period demand record for the 

 originality of their arrangements. In that of 

 Mr. Penman, of Newcastle, the bottom of the 

 hot-water tank was formed of vulcanised rub- 

 ber fabric, which rested loosely upon the eggs. 

 After a while this material " bagged " too much, 

 when the weight of the water was found to 

 crush the eggs and chickens, and the method 

 was consequently given up. We knew this 

 incubator to hatch well on several occasions, 

 however, and the defect stated could so easily 

 be remedied, that we have often wondered no 

 further attempt was made to carry out this 

 top contact system, along with more perfect 

 modern appliances. 



In the incubator of Mr. Boyle, top heat 

 was also used, but not quite in contact. The 



Fig. 34. — Boyle's Incubator. 



hot-water tank P, supplied by the pipe Q, was 

 shaped at the bottom into a series of arches, 



