certain
description given of the size or form of the supports or made up parts
to be temporarily fixed; all must depend upon the estimation of what
is best to be done under the circumstances; it can be likened to
engineering on a minute scale, quite as interesting, but less dangerous,
while more comfortably conducted in your own home without exposure to
the baleful influence of unsympathetic elements.

The next and most necessary proceeding will be the cleansing of the
surfaces that are to be permanently joined. In most instances the
application of clean cold water in a sponge will be sufficient, but
where much grime and grease have accumulated different means must be
resorted to. Soap is not to be recommended but, and especially if the
surfaces are irregular, some pure benzine, applied or slightly
scrubbed in by a stiff brush, not too large, and the parts then wiped
repeatedly on a clean cotton or other absorbent rag. Pure benzine, if
not rubbed in too hard or too long, will not injure the adjacent varnish,
be it the delicate film on a thousand pound gem of Cremona or the flinty
covering of a less presumptuous output from Naples. When evaporation
is complete, it will be so in a few minutes, some clean water brushed
in and wiped away, will leave the surfaces in a state for receiving
glue.

The glue should be of good strength--the junction being intended to
be permanent--and applied in a warm atmosphere or the parts warmed a
little, as, under different conditions the glue will coagulate or "set"
(diagram 18). When the parts are placed properly in position, and the
outside blocks or buffers adjusted for opposing pressure, the cramps
may be applied and screwed fairly tight. If the surfaces meet well and
the pressure is properly distributed, the glue will ooze out at the
juncture of the fractured parts. This can be wiped off with a cloth,
but occasionally mended parts cannot be got at easily, if so the glue
must be rubbed away after cramps and moulds have been removed, by a
damp sponge or cloth and then wiped dry. Sometimes differently to the
above mentioned simple fracture, it may be of the kind described by
surgeons as comminuted or split into small fragments. This will be
found to be much more troublesome than the former; after cleansing as
usual, if the injured parts are actually separated from the main
structure, judgment must be exercised in selecting those portions--the
largest if possible--that when glued in, will