plane, the canal widens out to 18 meters at the surface, with a depth
of 1.5 meter, and, through a sluice, joins the Osaka Bay Canal, after
a stretch of 2 kilometers.

[Illustration: FIG. 3.--AQUEDUCT OVER THE VALLEY OF THE TOMBS OF THE
EMPERORS.]

The second branch traverses a small tunnel, crosses the valley of the
emperors' tombs upon an aqueduct of 14 arches (Fig. 3), and reaches
Kogawa, a faubourg north of Kioto, after a stretch of 8 kilometers.
Its slope is greater than that of the main canal, from which it
derives but 1.4 cubic meter. The 7 cubic meters remaining may be
employed for the production of motive power under a fall of 56 meters.
It is proposed to utilize a portion of it, at the point of bifurcation
and at the top of the inclined plane, in a hydraulic installation that
will drive electric machines. The total cost of the work was one
million dollars, a third of which was furnished by the imperial
treasury, a quarter by the central government, and the rest by various
taxes.--_La Nature._

* * * * *

HOW TO FIND THE CRACK.--Most mechanics know that by drilling a hole at
the inner end of a crack in cast metal its extension can be prevented.
But to find out the exact point where the crack ends, the _Revue
Industrielle_ recommends moistening the cracked surface with
petroleum, then, after wiping it, to immediately rub it with chalk.
The oil that has penetrated into the crack will, by exudation,
indicate the exact course and end of the crack.

* * * * *

FAST AND FUGITIVE DYES.[1]

[Footnote 1: A paper recently read before the Society of Arts,
London.]

By Prof. J.J. HUMMEL.

As it is with many other arts, the origin of dyeing is shrouded in the
obscurity of the past; but no doubt it was with the desire to attract
his fellow that man first began to imitate the variety of color he saw
around him in nature, and colored his body or his dress.

Probably the first method of ornamenting textile fabrics was to stain
them with the juices of fruits, or the flowers, leaves, stems, and
roots of plants bruised with water, and we may reasonably assume that
the primitive colors thus obtained would lack durability.

By and by, however, it was found possible to render some of the dyes
more permanent, probably in the first instance by the application of
certain kinds of earth or mud, as we know to be practiced by the Maori
dyers of to-d