en table, secured to the upper edge of the board, H, is
perforated to allow the saw to pass through, and is provided with an
inserted hardwood strip which supports the back of the saw, and which
may be moved forward from time to time and cut off as it becomes worn.
The upper guide of the saw consists of a round piece of hard wood
inserted in a hole bored in the end of the arm, J. The upper end of
the saw is secured in a small steel clamp pivoted in a slot in the end
of a wooden spring secured to the top of the arm, J, and the lower end
of the saw is secured in a similar clamp pivoted to the end of the
wooden spring, K. Fig. 10 is an enlarged view showing the construction
of clamp.

The relation of the spring, K, to the board, H, and to the other part
is shown in Fig. 9. It is attached to the side of the board and is
pressed upward by an adjusting screw near its fixed end.

The saw is driven by a wooden eccentric placed on the saw mandrel
shown in Figs. 1 and 2, and the spring, K, always pressed upward
against the eccentric by its own elasticity, and it is also drawn in
an upward direction by the upper spring. This arrangement insures a
continuous contact between the spring, K, and the eccentric, and
consequently avoids noise. The friction surfaces of the eccentric and
spring may be lubricated with tallow and plumbago. The eccentric may,
with advantage, be made of metal.

The tension of the upper spring may be varied by putting under it
blocks of different heights, or the screw which holds the back end may
be used for this purpose.

The saw is attached to the lathe by means of an iron bent twice at
right angles, attached to the board, H, and fitted to the tool rest
support. The rear end of the sawing apparatus may be supported by a
brace running to the lower part of the lathe or to the floor.

The simple attachments above described will enable the possessor to
make many small articles of furniture which he would not undertake
without them, and for making models of small patterns they are almost
invaluable.

* * * * *

A NEW METHOD OF KEEPING MECHANICAL DRAWINGS.[1]

[Footnote 1: A Paper by Chas. T Porter, read before the American
Society of Mechanical Engineers.]

The system of keeping drawings now in use at the works of the
Southwark Foundry and Machine Company, in Philadelphia, has been found
so satisfactory in its operation that it seems worthy of being
communic