372 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
The greatest improvement, and the one used almost exclusively when ice and salt 
form the freezing agency, originated in 1868 with Mr. William Davis, of Detroit, 
Mich.,* the description being as follows: 
Two thin sheet-metal pans, or a box in two parts, are made one to slide over the other, the object 
being to place tlie fish in one pan, slide the other pan vertically over it, and the box is then placed in 
direct contact with the freezing mixture. By having the box constructed in this manner, it is capable 
of being expanded or contracted to accommodate the size of whatever may be placed therein, and 
the top and bottom always be in contact with the articles to be frozen. After the fish are inclosed in 
the pans, the latter are placed in alternate layers with layers of the freezing mixture between and 
about them. When the fish are thoroughly' frozen they' are removed from the freezing pans and jdaced 
in a cold-storage chamber in which the temperature is kept 12 or 14 degrees below the freezing point. 
Another arrangement for bringing the fish in contact with the ice was devised 
and patented by a fish-dealer of Toledo, Ohio, t as follows: 
A chest is so constructed that cells or compartments of various sizes may be formed in it for the 
reception of articles to be frozen, this being accomplished by having the walls of each compartment 
movable and each separated from the other by blocks of sufficient size to closely contain the articles 
placed therein, usually from 2 to 6 inches, and the freezing being effected by filling the spaces 
between the cell walls with salt and crushed ice. The sides’ of the cells or compartments are made 
of thin metallic plates, so that the upper end of each pair may be brought together, forming a closed 
compartment, to prevent the entrance of the refrigerating mixture into the fish chambers while filling 
the salt and ice compartments. To freeze a quantity' of fish by this method, they are placed in the 
open cells or compartments, head downward, as is most convenient. When each cell is full, the top 
edges of the sides are brought together and held in that position by clamps. The spaces between the 
cells, varying from 2 to 4 inches across, are then filled with the freezing mixture and the cover of the 
chest shut down. The cold produced passes through the wall separating the mixture from the fish 
and quickly freezes the latter. Provision is made for permitting the water formed by the melting ice 
to flow in grooves to suitable outlets, the bottom pieces of the cells keeping the fish dry. When the 
fish are frozen, the cover of the chest is raised, the contents removed, and the fish transferred to the 
storage freezer. 
This method of freezing was used only a few years, the pan process being found 
much more practicable. 
With a view to bringing the fish more closely in contact with the freezing mixture, 
some dealers at first used thin sheet-rubber bags, or other wateri)roof sacks, in which 
the individual fish were placed and then surrounded by the salt and ice, thus exposing 
the entire surface of the fish, resulting in much more rapid freezing. When the 
fish were frozen the sacks were removed and were dipped in water, which thawed them 
sufiiciently to permit the fish to be withdrawn. This method was abandoned after 
a year or two. 
To facilitate the shipment of frozen fish in barrels, Messrs D. W. & S. H. Davis, of 
Detroit, Mich., introduced f a process by which the fish are frozen in circular pans of 
varying sizes suited to the measurements of the barrels. After being frozen, the 
contents of each pan are removed entire and placed in appropriate position in the 
barrel, and the barrel headed and placed in cold storage. 
In 1877 C. W. Gauthier patented § a modification of the preceding method, using 
thin pliable partitions in the circular pans for separating each fish from its neighbor, 
so that the individual fish in each pan may be packed in the barrel separately. 
None of the last four iirocesses has ever been used to any considerable extent. 
* Letters patent No. 85913, January 19, 1869. 
t Letters patent No. 109820, December 6, 1870. 
t Letters patent No. 165596, dated April 6, 1875. 
^ Letters patent No. 187122, dated February' 6, 1877. 
