upon a gigantic scale.

Great interests are involved; large sums of money are being expended
in the erection and maintenance of expensive plant for its production;
and the author submits that the development of any method which will
improve the quality and at the same time reduce the cost of
manufacture of this valuable material will tend to increase the
prosperity of one of our great national industries, and stimulate
commercial enterprise. Works are in progress for manufacturing cement
by this improved process, and the author trusts the time is not far
distant when the unsightly structures which now disfigure the banks of
some of our rivers will be abolished--the present cement kilns, like
the windmills once such a common feature of our country, being
regarded as curiosities of the past, and cement manufacturers cease to
be complained of as causing nuisances to their neighbors.

* * * * *




MIX AND GENEST'S MICROPHONE TELEPHONE.


We illustrate in the annexed engraving the microphone-telephone
constructed by Messrs. Mix & Genest, of Berlin, which, after extended
trials, has been adopted in preference to others by the imperial
postal department of Germany. There are now more than 5,000 of these
instruments in use, and we need scarcely mention that the invention
has been patented in many countries.