HOW TO MAKE VIVARIA, 15 
little buttons running over the extending zine will hold the lid 
quite securely. The drawer, which may be dispensed with, 
should be made of wood. 
When Reptiles and Batrachians are not allowed to undergo 
their natural hibernation, they must be provided with artificial 
heat, which may easily be supplied with little trouble and at a 
trifling expense. Fig. 6 represents a winter case for Snakes and 
another for Lizards, both heated by the same lamp. 
A cylindrical zinc or tin boiler (Fig. 7), about two-thirds of the 
length of the Vivaria, is enclosed in the case B, Fig. 6. This 
boiler may be made without difficulty by taking two empty Sanitas 
or other tins of a suitable size, and driving the opening of one 
into the opening of the other, and soldering them together. If 
the tins are about Yin. long, and 3}in. in diameter, they will 
be quite large enough to heat 
properly cases of the size of 
those represented in Fig 6. 
An Aspinall tin (which can 
be made clean by placing it 
Fic. 7.—A, ZINC OR TIN BOILER; Bandc, : : 
lin. Gas-pipes, soldered in tothe Boiler; for a time in very hot water 
p, much smaller Boer Joined fo the and soda) will do eapitally for 
Gas-pipe. the smaller boiler. The top 
of p, Fig. 7, should be well 
below that of a. The lid of the smaller boiler must be 
soldered in its place. 8B, Fig. 7, is a leaden pipe for filling the 
boilers. As there is no other opening to the boilers, a little care 
is required to fill them properly with water. But this can easily 
be done by means of a small india-rubber siphon of a diameter 
considerably less than that of the pipe; this will allow the air to 
escape as the water runs in. While the boiler is in use, a little 
water should in this way be added occasionally to make up for 
loss. 
Fig. 8 represents the interior of B, Fig. 6, when the boiler is 
in its place. The bottom of a, Fig. 6, and the top of c, Fig 6, 
_are made of finely-perforated zinc. A fits exactly into the top of 
B, resting there on little ledges which are nailed inside, and B 
stands evenly upon the top of c. And in order that there may 
be no unnecessary loss of heat, the edges of c at the top are 
