led the ebulator system. The oil was pumped
up from the cooling tanks through the pipe _A_ to the tank _B_.
From here it ran down onto the breakers or separators _C_, which
break the oil up into fine particles that are caught by the fans
_D_. The spray is blown up into the cooling tower _E_, which contains
banks of cooling pipes, as can be seen, as well as baffies _F_. The
spray collects on the cool pipes and forms drops, which fall on
the curved plates _G_ and run back to the oil-storage tank below
ground.

The water for this cooling was pumped from 10 artesian wells at the
rate of 60 gal. per minute and cooled 90 gal. of oil per minute,
lowering the temperature from 130 or 140 to 100 deg.F. The water as
it came from the wells averaged around 52 deg.F. The motor was of a
7-1/2-hp. variable-speed type with a range of from 700 to 1,200
r.p.m., which could be varied to suit the amount of oil to be cooled.
The plant handled 300 gal. of oil per minute.

CHAPTER VI

ANNEALING

There is no mystery or secret about the proper annealing of different
steels, but in order to secure the best results it is absolutely
necessary for the operator to know the kind of steel which is to
be annealed. The annealing of steel is primarily done for one of
three specific purposes: To soften for machining purposes; to change
the physical properties, largely to increase ductility; or to release
strains caused by rolling or forging.

Proper annealing means the heating of the steel slowly and uniformly
to the right temperature, the holding of the temperature for a given
period and the gradual cooling to normal temperature. The proper
temperature depends on the kind of steel, and the suggestions of the
maker of the special steel being used should be carefully followed.
For carbon steel the temperatures recommended for annealing vary
from 1,450 to 1,600 deg.F. This temperature need not be long continued.
The steel should be cooled in hot sand, lime or ashes. If heated in
the open forge the steel should be buried in the cooling material
as quickly as possible, not allowing it to remain in the open air
any longer than absolutely necessary. Best results, however, are
secured when the fire does not come in direct contact with the
steel.

Good results are obtained by packing the steel in iron boxes or
tubes, much as for case-hardening or carbonizing, using the same
materials. Pieces do not require to be entirely surrounded by carbon
for an