191 



ARTrp^iriAL fYCUBATIOlV. 



There is an old proverb tliat warns us, "not to count our chickens 

 before they are hatched," but modern science has gone very far towards 

 changing contingency to certainty. Perhaps we ought to leave away 

 that boastful word, '■modern^'' for we are told that the Egyptians have from 

 time immemorial, practiced and preserved the art of lialcliing cliickens 

 in brick ovens, which they term jnamals. But the Egyptian process is 

 a very imperfect one, and it is only recently that the application of cor- 

 rect principles of chemistry and physiology to the construction of suit- 

 able machinery, and to the proper development and care of birds, parti- 

 cularly domestic fowls, has enabled the skillful poulterer to increase his 

 production to almost any amount, or, at least, determine how many doz- 

 en of chickens he will bring forth from the Qgg. 



It has long been known that about 104° of heat is the temperature 

 to which eggs are raised by the incubation of the common domestic 

 fowl. From this it was easy to infer, that all that was necessary to the 

 production of the chicken from the egg^ was the uninterrupted appli- 

 cation of about that amount of heat for the proper time. Reaumer en- 

 deavored to secure this b)^ the fermentation of manure in suitable casks 

 or ovens, but his success was by no means great. A much surer method 

 is that of applying warm water to the vessel in which the eggs that are 

 to be hatched are placed. This is done in the "Artificial Hen," and the 

 "Calefactor" of Lemaire, and some other contrivances which are described 

 in the '■^Maison Rust i que,'''' a French agricultural paper, an article in 

 which, upon this subject, is translated for the '•'•Boslon Chronicle,'''' from 

 which we gather the following facts : 



The best apparatus for incubation upon a large scale is that of Sorel. 

 This is formed by a large, cylindrical, copper boiler, perforated through 

 the middle to give passage to the chimney, which rises above it, and by 

 which escape, not through the upper part which is closed, but througli 

 holes made in the circumference, the gaseous products of the combus- 

 tion of a lamp or small fire of charcoal placed on the hearth. The boil- 

 er is enlarged both at its upper and lower part, to form in both cases 

 hollow discs in which the hot water diffuses itself. These two discs 

 also communicate with each other by a certain number of columns, or 

 vertical tubes, placed at intervals around the apparatus. These columns 

 descend quite to the platform of the fireplace, which is itself a double 

 bottom, in which the water can diffuse itself. The upper surface of the 

 boiler is in the shape of a cover, which can be raised at pleasure, either 

 to fill it with water or to adjust the float. This float is a vessel invert- 

 ed, placed in the centre of the boiler, and surmounted with a cylinder 



