CONVERSAZIONE. 
683 
crystals in polarized light; frames containing a set of Dr. Maddox’s photo¬ 
micrographs ; a frame with a set of electrotypes from the Mudie national me¬ 
dals ; specimens of carbon printing ; a photograph from a sketch by Fid, ‘ The 
Drama, Past and Presentand a powerful medical coil-machine, with primary 
and secondary currents (in action), by Mr. How: a collection of apparatus 
for the indication of fire-damp in mines or coal-gas in houses ; a large steel 
shaving (said to be the largest ever cut) from the works of Sir John Brown 
and Co., of Sheffield ; a portion of the slag formed by burning forged notes and 
documents, as well as base coin, at the Bank of England ; and part of the slag 
formed by burning a mass of Bank of England notes ; by Mr. George F. An- 
sell: and a collection of apparatus for estimating the value of lubricating oils, 
by Professor Redwood. 
Microscopes were exhibited by Mr. Ross ; Messrs. R. and J. Beck ; Messrs. 
Horne and Thornth waite ; Messrs. Murray and Heath; Mr. Collins; Mr. 
How ; aud Mr. Edward Histed. 
Commander Bourchier exhibited models and diagrams illustrating Welsh 
and Bourchier’s apparatus for saving and preserving life at sea. This is 
proposed as a substitute for the life-buoys at present in use, over which it 
appears to possess several advantages. It consists of an air-tight casing of 
metal with a lattice-work bottom, the upper part of the casing providing 
the buoyant power, wffiile the lower part is formed into a tank for fresh 
water. 
The apparatus is provided with a couple of weighted rods to give stability 
in the water, and two tall masts furnished with flags and port-fires to guide 
the swimmer to the buoy and to ensure his being afterwards seen and picked 
up. These rods and masts are made telescopic to economize space, and are 
not visible until the apparatus is, by pulling out a single bolt, released from 
its supports on board ship and falls into the water, when they immediately 
shoot out from the interior of the apparatus ; the fall of the weighted rods 
raising the masts. Once within the apparatus (and we are assured that it is 
easier to get in than to get out), a man is comparatively comfortable : nearly 
half his body is out of water ; the sharks cannot touch him ; and, above all, 
his safety does not depend upon his retaining sufficient strength to grasp the 
buoy. Should he be so unfortunate as not to be picked up within a reason¬ 
able time, he has in his cistern of water the means of prolonging life for a 
couple of days, and we believe that the inventors intend, that the apparatus 
shall be provided in addition with a tin of preserved meat. 
Mr. F. N. Gisborne exhibited his patent balance-weight steering signals ; 
some specimens of Gisborne’s anti-corrosive paints, which do not soften under 
water ; a new form »of telegraph post, with internal insulation ; Gisborne’s 
magnetic torpedo trigger; a specimen of Horsley’s powder, with an iron 
plate showing its enormous power ; and some specimens of gold quartz from 
Hova Scotia. 
' Considerable attention was attracted by an exhibition of apparatus by 
Messrs. A. M. and M. A. Wier, illustrating their new system of atmospheric 
telegraphy, for railways, ships, mines, warehouses, hotels, etc. The collec¬ 
tion comprised the following instruments, all being in operation during the 
evening, aud appearing to work most satisfactorily:— 
Wier’s atmospheric telegraph, for communicating orders between captains 
and engineers, or between captains and helmsmen ; for automatically showing 
the position of the helm ; for registering on deck, or in the captain’s cabin, 
the revolutions of the engine ; for automatically showing red and green lights 
at the mast-head, to prevent collisions at sea ; for working Major Bolton’s 
system of flash lights ; and for fighting guns and giving orders on board men- 
of-war, etc. 
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