nger is removed from D. This stops the flow instantly. This method
is the most satisfactory one when fairly large quantities of acid or
water are to be drawn off.

SHOP LAYOUTS

The degree of success which the battery repairman attains depends to a
considerable extent upon the workshop in which the batteries are
handled. It is, of course, desirable to be able to build your shop,
and thus be able to have everything arranged as you wish. If you must
work in a rented shop, select a place which has plenty of light and
ventilation. The ventilation is especially important on account of the
acid fumes from the batteries. A shop which receives most of its light
from the north is the best, as the light is then more uniform during
the day, and the direct rays of the sun are avoided. Fig. 38 shows a
light, well ventilated workroom.

The floor should be in good condition, since acid rots the wood and if
the floor is already in a poor condition, the acid will soon eat
through it. A tile floor, as described below, is best. A wooden floor
should be thoroughly scrubbed, using water to which baking soda has
been added. Then give the floor a coat of asphaltum paint, which
should be applied hot so as to flow into all cracks in the wood. When
the first coat is dry, several more coats should be given. Whenever
you make a solution of soda for any purpose, do not throw it away when
you are through with it. Instead, pour it on the floor where the acid
is most likely to be spilled. This will neutralize the acid and
prevent it from rotting the wood.

If you can afford to build a shop, make it of brick, with a floor of
vitrified brick, or of tile which is not less than two inches thick,
and is preferably eight inches square. The seams should not be less
than one-eighth inch wide, and not wider than one fourth. They should
be grouted with asphaltum, melted as hot and as thin as possible (not
less than 350 deg. F.). This should be poured in the seams. The brick or
tile should be heated near the seams before pouring in the asphaltum.
When all the seams have been filled, heat them again. After the second
heating, the asphaltum may shrink, and it may be necessary to pour in
more asphaltum.

If possible, the floor should slope evenly from one end of the room to
the other. A lead drainage trough and pipe at the lower end of the
shop will carry off the acid and electrolyte.

It is a good plan to give all work benches and storage racks and
she