Washes.

(1) Lime stew. (1) Wash.
(2) Sour. (2) "
(3) Gray bowk (3) "
(soda ash).
(4)I Chemic. (4) "
(5) Sour. (5) "
(6) White bowk. (6) "
(7)II Chemic. (7) "
(8) Sour. (8) "

It will be understood that 2 and 2a are merged into a single process by
using the "continuous" machine. Of course, it will be understood that the
cloth has in each case to be cleansed from size and loose impurities. The
"Mather-Thompson" Company claim that their system takes twelve hours in
the case of "market" or "white" bleaching. They reckon eight hours for
the steaming process and four for bleaching and washing. This has to be
compared with the old system, which generally takes forty hours, made up
as follows: 8 treatments with reagents and the necessary washings, the
former taking four hours and the latter one hour each.

The "Mather-Thompson" system has created considerable commotion in
English bleaching circles. It is generally considered that the bleachers
throughout the whole country will be compelled to adopt it, so great is
the saving in time and cost. In commencing a bleachery, the cost of
plant by this system is, I understand, less than by the old
processes.--_Textile Colorist_.

* * * * *

INSTRUMENTS FOR DRAWING CURVES.

By Prof. C.W. MacCord, Sc.D.

I. THE HYPERBOLA.

We are free to express the opinion at the outset, that for various
reasons the draughtsman is likely to gain very little advantage by the
use of mechanical devices for describing mathematical curves by
continuous motion. Such instruments are as a rule not only complicated
and expensive, but cumbersome and difficult of adjustment. It may be
suggested, _per contra_, that these objections do not apply to the
familiar combination of two pins and a string, for tracing the
"gardener's ellipse." But we question the propriety of classing a string
among strictly mechanical devices; it has its uses, to be sure, but in
respect to perfect flexibility and inextensibility it cannot be relied on
when rigid accuracy is required in drawing any of the conic sections.

[Illustration: FIG. 1.]

Nevertheless, t