HOW TO MAKE VIVARIA. 17 
keep it at the necessary temperature. If the air in the Vivaria 
becomes too hot, the curtain or piece of felt which is cut to lie 
over D, Fig. 6, can be turned back, and the flame of the lamp 
lowered. The lamp, if desired, can be hidden from sight by a 
little wooden or metal screen, made to slide over it. I believe, 
after many experiments, that cylindrical, and not too large, 
boilers are the best kind to use for such a purpose as the above. 
In summer, when no artificial heat is required, these cases can 
easily be detached and used separately, and the boiler, etc., put 
away for another winter. 
The boiler case (Fig. 8), should have a wooden bottom, covered 
inside thickly with sawdust or folded paper, when it is intended 
to be used for heating only one Vivarium, e.g., one like that re- 
presented by Fig. 3. And unless gas be convenient as a source 
of heat, it ought to be provided with legs or a stand, so that a 
small lamp may be placed beneath the outside boiler. Of course, 
it could easily be arranged that the boiler case, the bottom being 
left open and the top enclosed, should be placed above the single 
Vivarium (it being provided witha perforated zinc top), and then 
there would be no need of a stand or legs. This device has its 
advantage, since the Lizards or Snakes within the case would be 
tempted to spend a great portion of their time upon the branches 
of the tree, and so be well exposed to view, and more likely to 
become very soon quite tame. 
Fig. 9 is a Fernery and Vivarium combined. It is fairly easily 
made, and if well done, well arranged and cared for, is very 
ornamental and interesting. Certain Reptiles and Batrachians 
will live all the year round in it, apparently happy and contented. 
The bottom (a) is made of wood and lined with zinc, or covered 
inside thickly with pitch. It is provided, at some convenient 
spot, with a small pipe used for drainage purposes. The frame- 
work for the glass can be made of either wood or zine as de- 
scribed for Fig. 3. That portion of the top of this Vivarium, 
marked @, is covered with perforated zinc for ventilation. B is 
a sheet of glass made to slide completely over the zinc, so that 
all outside air, when necessary, may be excluded. ~If the 
Vivarium must be so placed that the sliding sheet of glass (B) 
would be in the way when open, it (the glass) should be placed 
c 
