IMPROVEMENTS IN THE MEANS AND APPARATUS EMPLOYED FOR FREEZING LIQUIDS
Year: 1868

page_text: PROVISIONAL SPECIFICATION left by Alexander Melville Clark at
the Office of the Commissioners of Patents, with his Petition, on
the 9th March 1868.-A communication from abroad by Guillaume
Toselli, Merchant, of 29, Boulevart St. Martin, Paris.
I, ALEXANDER MELVILLE CLARK, of 53, Chancery Lane, in the
County of Middlesex, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN THE MEANS AND APPARATUS EMPLOYED FOR
FREEZING LIQUIDS," to be as follows:-
This Invention relates to apparatus intended more particularly for
making small quantities of ice.
In the annexed Drawing, A, Figure 1, is a container of metal or
other suitable material; if the sides are of a single thickness of metal
it should be covered with wool, felt, or other non-conductor of heat.
In the vessel A. is introduced a conical vessel B, Figure 2, in which
are placed the liquids to be converted into ice. The vessel B is provided
with a rim or flange of india-rubber C, D, above in order to obtain
an hermetic closure by means of the cover, which is fixed on by a
screw E, Figure 3, carried in a cross piece F, G, whose ends grip the
edge of vessel A, as shown at Figure 4.

page_text: Method of Operation.-In order that the refrigerating mixtures
employed may be quite harmless, I use exclusively for the purpose
the subcarbonate of soda and hydrochlorate of ammonia in the pro-
portions of two parts of each salt to four parts of fresh water, or I use
subcarbonate of soda with pure nitrate of ammonia, in the proportions
herein-after indicated, that is to say, I introduce into the smaller
vessel B one part of water or other liquid to be converted, and then
place in vessel A two similar proportions of fresh water and two parts
of each salt. I then place vessel B in vessel A and apply the cover
as before mentioned, and taking the small machine in the hand I
invert and shake it to and fro, either in a vertical, horizontal, or other
direction for about six minutes if the product is to be merely iced, or
for ten minutes if ice is to be produced.
I would here observe that glass and stoneware vessels have been used
for containing the refrigerating salts, as also cases of tin and other
material; but I prefer to employ beech wood for the purpose as more
perfectly preserving said refrigerating salts, while it is at same time
light, strong, and economical.
The improvements thus consist,―
First. In the mode of enclosing the two liquids, as described and
represented in Figures 3 and 4 of the Drawing.
Secondly. In the employment as refrigerating substances of a mixture
of subcarbonate of soda and hydrochlorate of ammonia, in the pro-
portions before indicated as being the only ones of a harmless nature
which may be used without danger or difficulty.
Thirdly. In producing the desired result by the simple motion of the
hand, as described, whereby to effect the simultaneous shaking and
mixing of the refrigerating salts with the liquid to be acted on.
Fourthly. I may make the inner vessel of greater length and smaller
diameter, as shown at Figure 5, instead of being short and wide as in
Figure 2, the sides being either plain or of the form shown in Figure 6,
when making ice cheeses, for example.