lame. As
asbestos absorbs moisture, which would defeat its use as an annealing
material, it must be dried if necessary.

(5) A Glass-Cutter's Knife. This is best made out of a fine
three-cornered file, with the file teeth almost ground out, but not
quite; it should be about 2 inches long. After the surface has been
ground several times, it may be necessary to reharden the steel. This
is best done by heating to a full red and quenching in mercury. The
grindstone employed for sharpening the knife should be "quick," so as
to leave a rough edge. I have tried many so-called glass knives "made
in Germany," but, with one exception, they were nothing like so good
as a small French or Sheffield file. In this matter I have the
support of Mr. Shenstone's experience.

(6) A wire nail, about 2 inches long, mounted very accurately in a
thin cylindrical wooden handle about 5 inches long by one-quarter of
an inch diameter, or, better still, a bit of pinion wire 6 inches
long, of which 1.5 inches are turned down as far as the cylindrical
core, An old dentists' chisel or filling tool is also a very good
form of instrument.

(7) A bit of charcoal about 3.5 inches long and 2 wide, and of any
thickness, will be found very useful in helping to heat a very large
tube. The charcoal block is provided with a stout wire handle, bent
in such a manner that the block can be held close above a large glass
tube on which the flames impinge. In some cases it is conveniently
held by a clip stand. By the use of such a slab of charcoal the
temperature obtainable over a large surface can be considerably
increased.

I have seen a wine-glass (Venetian sherry-glass) worked on a table
with four blow-pipes, such as is here described, with the help of a
block of hard wood held over the heated glass, and helping the
attainment of a high temperature by its own combustion.

(8) Several retort stands with screw clips.

(9) Some blocks of wood about 5" X 2" X 2" with V-shaped notches cut
in from the top.

(10) A strong pair of pliers.

(11) An apparatus for cleaning and drying the breath, when blowing
directly by the mouth is not allowable. The apparatus consists of a
solid and heavy block of wood supporting a calcium-chloride tube
permanently connected with a tube of phosphorus pentoxide divided into
compartments by plugs of glass wool. Care should be taken to arrange
these tubes so as to occupy the smallest space, and to have the stand
partic