become clogged. The generator should then be filled with the required
amount of water. In charging carbide feed machines be careful not to place
less than a gallon of water in the water compartment for each pound of
carbide to be used and the water must be brought to, but not above, the
proper level as indicated by the mark or the maker's instructions. The
generating chamber must be filled with the proper amount of water before
any attempt is made to place the carbide in its holder. This rule must
always be followed. It is also necessary that all automatic water seals
and valves, as well as any other water tanks, be filled with clean water
at this time.

Never recharge with carbide without first cleaning the generating chamber
and completely refilling with clean water. Never test the generator or
piping for leaks with any flame, and never apply flame to any open pipe or
at any point other than the torch, and only to the torch after it has a
welding or cutting nozzle attached. Never use a lighted match, lamp,
candle, lantern, cigar or any open flame near a generator. Failure to
observe these precautions is liable to endanger life and property.

_Operation and Care of Generators._--The following instructions apply
especially to the Davis Bournonville pressure generator, illustrated in
Figure 11. The motor feed mechanism is illustrated in Figure 12.

Before filling the machine, the cover should be removed and the hopper
taken out and examined to see that the feeding disc revolves freely; that
no chains have been displaced or broken, and that the carbide displacer
itself hangs barely free of the feeding disc when it is revolved. After
replacing the cover, replace the bolts and tighten them equally, a little
at a time all around the circumference of the cover--not screwing tight in
one place only. Do not screw the cover down any more than is necessary to