34 
The Australasian Book of Poultry. 
ordinary bell battery so that, when the current passed through, instead of ringing a bell the armature was 
attracted to the poles of the magnet, thereby opening a damper that was carefully hinged. The machine in 
my hands was a great success, but the mechanism was too delicate for ordinary use. I used ordinary 
Le Clanche cells, but recommend the Daniell's as being more constant. I afterwards had some special 
thermometers made for me by Casella, of London ; they were obtained through Mr. Boettger, of Adelaide 
(S.A.). Some years afterwards I noticed in a Sydney paper that a patent had been taken out in England for 
this identical thermometer, under tlie name of an " Electric Thermostat." Mr. Boettger has a press copy of 
the original drawing. A friend of mine had an electrically-regulated machine, but he broke all the stock of 
thermometers, and I then thought out the regulator described in the following lines. This was in 1890. In 
other respects both machines were identical. I herewith give explanations and diagrams. 
How TO Make an Incubator. 
The following sketches are not drawn to scale, but a full explanation should remedy any such deficiency. 
Incubators may be made of any size, from i-egg up to 1,000-egg capacity. If larger machines are required it 
is better to con.->truct them on a different principle, although retaining the main points. There are already 
numerous machines on the market, some good, some indifferent ; all have their champions, but we do not 
Fig. 26 — Front Elevation. 
deal with them, beyond stating that the general shape of the machine here explained is similar .to that made 
by Messrs. Christy, Muir, Hearson, and others, and is the result of much careful experimenting also. 
Material. 
The woodwork may be of American lumber (shelving), flooring-boards, red pine, clear pine, or cedar ; it 
must be well seasoned, and free from knots, etc. There are other woods which would, no doubt, do ; but 
the above are lair. For the outside casing the wood is to be from three-quarters of an inch for small, up to 
an inch and a quarter for the very large machines. The case may either be screwed together or dovetailed, 
according to the wishes of the maker. The double mitre joint is a good one for the purpose. The stops, 
fillets, etc., to fix the tank may be of any sort of wood. The runners for the drawers should be of hardwood, 
and well soaped or black-leaded. The tank and boiler may be made of best galvanized iron, 24-gauge, or, if 
great durability is expected, sheet copper or brass may be employed. 
Fig. 26 shows the general appearance of the machine when looked at from the front. Here the machine 
is standing on legs, wliich may be of any convenient height. The lamp-house and boiler are at the left-hand 
end of the machine, the tap or outlet at the opposite end. Underneath the egg-drawer is a space about an 
inch and a half deep, to contain the pans to supply the eggs with moisture during incubation. The lamp 
consi-sts of a tin reservoir and a Bismarck burner for the larger machines, and for the smaller ones tlie 
Aladdin burner without a chimney, or with a cardboard chimney and mica-covered opening. . The small 
