110 
POPULAR SCIENCE REVIEW. 
salt, and after drying, a coat of clear gelatine brings to tbe next process that 
of transferring, which is accomplished by placing a damp mounting board 
on the gelatine surface and passing the two through a rolling press. This done, 
when quite dry a piece of cotton wool saturated with benzole rubbed over 
the surface of the paper attached to the benzole, softens the latter, and 
admits of the former’s removal. 
Photography and Navigation. — A Novel Application. — M. Carradi of Mar- 
seilles proposes to register the path of a ship, and its various tackings and 
evolutions, by means of photography. For this purpose he has contrived an 
instrument which he calls a “ loxodograph,” which consists of a compass 
placed below the ordinary ship’s compass, so as to occupy the same relative 
position in the ship, and so that it can be compared from time to time with 
the normal instrument. Underneath the secondary compass is some simple 
clockwork, having for its object the unrolling of a band of sensitised paper, 
of a width equal to the diameter of the card of the compass. This paper is 
placed horizontally under the compass, and unrols, longitudinally following 
the axis of the vessel. Underneath the disc of the compass, but above the 
paper, and placed at the north pole, is a lens, which projects a luminous 
point upon the paper below. Thus, if the ship pursue a straight line, from 
north to south, for example, the luminous point will be thrown upon the 
paper, and trace a straight line also from north to south ; if, on the 
contrary, the ship move in an irregular broken course, the bright point 
will be shown on the paper in a line of the same character, seeing that the 
paper follows the ship’s movements, whilst the luminous point remains 
stationary at the north. We extract this description from the British Journal 
of Photography. 
Something Sensational. — A strange story is told in Les Mondes. A Dr. 
Marina, to advertise a method he had invented of preventing decomposition 
after death, had operated upon the body of a deceased literary man, named 
Pietro Martinis, who died on February 17 last. On the body being dug up, 
on June 17 last, it was so supple and life-like that it was dressed up in the 
author’s u habit as he lived,” taken to a glass room, and photographed. 
PHYSICS. 
New Instrument for Registering the Speed and Pressure of the Wind. — Mr. 
John Browning has nearly completed, under the supervision of the As- 
tronomer Boyal and Mr. Glaisher, a set of instruments for the above-men- 
tioned purpose. The first, for registering the force of the wind, consists of 
a circular plate of metal, of a diameter equal to two square feet in area, 
supported by eight tempered steel springs. When the wind impinges on the 
circular plate the springs are brought consecutively into action, the stronger 
coming into play before the weaker have received any strain. The plate is 
kept constantly facing the wind by means of a direction- vane. From the 
plate a fine flexible wire is carried down through a hollow pillar which 
supports the vane, the whole apparatus being in a room below. The wire 
governs the motion of a pencil, which is made to traverse a table covered 
with slate, on which is strained a sheet of paper marked with the hours. 
