[Illustration: FIG. 2.]

The only thing to be done, where feed connections are made in the manner
described, is to change them, and by changing them at once much trouble,
or even a disastrous explosion, may be avoided. Put the feedpipe in
through the front head, at the point marked _p_ in Fig. 1, drill and tap
a hole the proper size for the feed pipe, cut a long thread on the end of
the pipe, and screw the pipe through the head, letting it project through
on the inside far enough to put on a coupling, then screw into the
coupling a piece of pipe not less than eight or ten feet long, letting it
run horizontally toward the back end of the boiler, the whole arrangement
being only from 3 to 4 inches below the water line of the boiler, and hot
or cold water may be fed indifferently, without fear of danger from
ruptured plates or leaky seams. In short, put in a "top feed," and avoid
further trouble.--_The Locomotive_.

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[MICROSCOPICAL JOURNAL.]

IRON PRINTING AND MICROSCOPIC PHOTOGRAPHY.

By C.M. VORCE, F.R.M.S.


I. FORMULAS FOR PRINTING SOLUTIONS.