e
room a curtain of ice drops to the floor, from a crevice extending
horizontally in the rock at the height of one's eyes. Close
examination discovers the water oozing from this crevice, and as it
finds its way down the side it freezes in the low temperature of the
chamber. Singularly this one crevice, and that no wider than a knife
edge, furnishes this, nature's ice house, with the necessary water. It
was a hot day in August, the thermometer marking 80 deg. in the shade
when the visit was made, and comparatively the cold was intense. In
common with all visitors, we detached some large pieces of ice and
with them hurriedly departed, glad to regain the warmth of the outside
world.

The most remarkable fact in connection with this wonder is that the
water only freezes in the summer. As the cold of actual winter comes
on the ice of the cave gradually melts, and when the river below is
frozen by the fierce cold of Northern Iowa, the ice has disappeared
and a muddy slush has taken the place of the frigid floor. I would add
that the ice chamber forms the terminus of the cave. Beyond a shallow
crevice in the crumbling rock forbids further advance. The rock
formation of this region is the Portland sandstone.

Why should the temperature of the ice chamber be such as to freeze the
water trickling into it? And above all, why should the ice disappear
with the cold of winter?

Mansfield, O. H. M. W.

* * * * *

THE WRITING TELEGRAPH.

On the evening of February 26, 1879, the writing telegraph of Mr. E.
A. Cowper, of London, was exhibited in operation before the Society of
Telegraph Engineers, in that city. It is a curious and remarkable
invention. By its use the handwriting of the operator may be
transmitted, but a double circuit, that is, two telegraph wires, are
used. The operator moves with his hand an upright pointer or stylus,
with which he writes the message on paper. The stylus has two arms
connected with it, one of which arms, when the stylus makes an upward
movement, causes a current to be sent over one wire, while the other
arm causes a current to pass over the other wire when the stylus is
moved laterally. These two motions are, at the receiving end of the
line, made to operate on the needles of galvanometers, and the latter
are by silk threads combined or connected with a delicately suspended
ink tube, from which a minute stream of ink falls upon the strip of
paper below it