The morning call., 1893-10-29
QUERY Column.
Welding of Metals by
Using Electricity.
ORIGIN OF THE FRENCH RACE.
Hints for Would.Be Applicants fol
Positions on the Police Force
and Fire Department.

tQueries reaching this office before Friday
evening will be answered the Sunday following.
Only questions that are of general interest will
be replied to. Do not inclose stamps expecting
personal reply.l
WELDING BY ELECTRICITY-J. III. D.,
City. Heat sufficient to weld metals may
be produced by current passing through
the point of junction or by the voltaic arc.
The current process is carried out by
pressing together The objects to be united
while holding them in conducting clamps.
a heavy current is turned on by way of
the clamps and rapidly heats the metals
at the junction, which Is OF course the
point Of highest resistance. AS the metal
softens 1t is pressed together, one OF the
clamps being mounted with feed motion,
flux Is dropped on If necessary and the
metal pieces unite. The most remarkable
results are thus obtained. Almost all the
common metals can be welded and differ
eDt metals can be welded together. Tubes
and other shapes can also be united. In
many cases the weld is the strongest part.
The alternating current Is employed and
special dynamo is sometimes used TO
produce it, This dynamo has two wind
ings on the armature, one OF nne wire,
and Is in series with the field magnets and
| eXcites them. The other Is OF copper bars,
| and connects with the welding apparatus,
| giving q current Of high intensity. In
| welding by the voltac arc the place to be
| heated is made an electrodo OF an arc by
| connection with one terminal OF an cleo
trio circuit carbon is connected to the
other terminal. An arc Is started. by
touching and withdrawal of the carbon.
The heat may be used for welding, solder
ing, brazing or even for perfOrating or di-
vidlng metal sheets. The Bernados cleo
| tric Welding process was secret until re-
Gently. 1t is described as follows: An
ordinary lighting. low-tension. continuous
current dynamo is USED; u 70 tne os
accumuators is connected. and into
this the current flows continuously. When
the welding circuit is closed the current
| flows from the dynamo and accumulateS
through large regulating resistance. One
terminal of the system is connected by
means of flexible cable to a carbon PEN
Gil fixed in an insulated holder. This is
held by the workman. The other terminal
| is connected to the table on which the
work lies or to the work itself. Thus the
carbon pencil forms one pole and the wOrK
| the other pole, and the electric arc is
| sprung between them. 1t is possible to
obtain an arc for welding purposes Blk
inches In length and having sectional
area OF about two square inches. When
iron or steel is under treatment 1t is usual
| to make the carbon the negative pole and
| the iron or steel the positive pole; for
other metals the poles are sometimes re-
versed.
POLICE AND FIREMEN-R. S., City. To
| become a member of the police force the
| applicant must stand at least feet
inches in his stockings and his chest meas
ure must exceed 81 inches. He must have
free use of all his limbs, and his hearing,
vision and speech must be perfect. He
must have no turnois or excessively cica
tried legs or rupture or culaneous affec.
tion. He must have no confusion or wound
on the head that might impair bis facul.