es continuously,
but has, at the same time, a to and fro motion in the direction of its
axis, so as to cause the thread to move forward constantly and form a
cop. This to and fro motion is obtained by means of a lever and a
sleeve, I, the wheel, H, of the shaft being set in motion by the pinion,
J, actuated by the transmission of the machine. As the spindle advances,
a core is formed; the click, F, is then pushed backward, and the cone is
kept in motion by the thread until the cop is finished.

[Illustration: A NEW COP-WINDING MACHINE.]

Preference is usually given to the horizontal model; but the system may
likewise be applied to a vertical spindle, and the arrangement in this
case is simpler, as shown in Fig. 3. A rotary motion of the shaft is
useless here, as the click, F, acts in an oblique position upon the
ratchet-wheel, O, and pushes it by reason of the to and fro motion of
the screw.

* * * * *

[Continued from SUPPLEMENT, No. 513, page 8191.]

THE PRESERVATION OF TIMBER.

[Footnote: From the Transactions of the Society.]

REPORT OF THE COMMITTEE OF THE AMERICAN SOCIETY OF CIVIL ENGINEERS ON
THE PRESERVATION OF TIMBER, PRESENTED AND ACCEPTED AT THE ANNUAL
CONVENTION, JUNE 25, 1885.

BOUCHERIE, OR SULPHATE OF COPPER.

The name of Dr. Boucherie is generally applied to the _process_, which
he invented and extensively applied, of preparing wood by forcing a
solution longitudinally through the pores of the wood by means of
hydraulic pressure. As, however, he also patented the use of sulphate of
copper, and his name became attached to the use of that antiseptic, it
will be convenient here to classify experiments made with that substance
under this head.

Dr. Boucherie was a distinguished French chemist, who between 1836 and
1846 made many elaborate researches and experiments upon the
preservation of timber. He tried many substances, and at first
recommended the use of pyrolignite of iron, but subsequently used
sulphate of copper, which he considered more effective.

His first experiments were conducted by vital suction, that is, by
tapping the living tree, and allowing the ascending sap to carry up a
preserving solution. This was not found to give uniform or satisfactory
results, and Dr. Boucherie then invented the process which bears his
name. This was practiced either by applying a cap to the end of a
freshly cut log, through which the solution was allowed to flow