PRFJSERVATION OF FISHERY PRODUCTS FOR FOOD. 
529 
ill the soldering, and it is at once resoldered, pnnctnred in two or more places, and 
placed in hot oil until it is again filled with oil, when the punctures are soldered. 
In 1884 it was discovered* that the process of venting could bo avoided by making 
the can with concave top and bottom. The depression of the middle part causes the 
air in the cans to collect about the edges of the top, and the heat of the soldering 
tool heats the air and causes it to e.xpand and escape in front of it as it passes along 
the edge, so that when the soldering is com[)leted the air will be sufficiently expelled. 
Venting is no longer practiced in preparing the ordinary quarter size, but it is gener- 
ally adhered to in the treatment of the half and three-quarter cans, t Some of the 
factories partly immerse the half and three-quarter cans in boiling oil, driving out the 
air and rendering venting unnecessary. 
In the specifications forming a iiart of the Letters Patent il^o. 2i>3G82, dated 
January 20, 1880, issued to the inventor of the rotary oven for baking, the following 
account is given of the methods of preparing sardines on the Maine coast, and the 
improvements effected by using that oven: 
After the fish are laiuted they are subjected to tlie process of decapitation aud disentrailiiient 
and salting for a suitable period. They are then washed clean aud placed in shallow ))askets to drain, 
after which they are separately spread on lath or other suitalde frames for drying to a certain extent. 
After the fish have been sufficiently dried by exposure to the atmosphere or to an artificial current of 
warm, dry air they are placed in shallow wire baskets, or any other suitable receptacle, and immersed 
in oil, suital)le in f|uality and heated to a certain degree, for the purpose of frying and expelling from 
the fish any parts of water which remain in them after the drying process. They are then allowed to 
drain, and are packed in tin cans. This mode of drying by natural or artificial currents of air and 
frying the fish in oil is, for reasons hereinafter stated, very deleterious to the quality of the article of 
fish to be put up, and the invention herein set forth tends to do away with and overcome the former 
objectionable method. The fish used for the purpose Indicated are of a very tender and delicate 
nature. They do not admit of much handling, and, owing to this delicacy of nature, are subject to 
very rapid decomposition, as they should bo salted but very slightly. 
The process of drying the fish, either in open air or by an artificial current of warm dry air, 
takes so much time, that decomposition of the fish to a greater or less extent is unavoidable, as 3 to 2i 
hours are consumed in drying the fish sufficiently by the modes indicated. 
In frying the fish in oil, as now i)racticed, the quality of the oil in which ([uantities of fish are 
fried is rapidly deteriorated by the water from the fish, which is not evaporated, and from the gluten 
from the fish passing into it. A large percentage of the fish is also lost by breaking during the process 
of frying in oil. In our improved process the fish, after landing, are decapitated, diseutrailed, salted, 
and washed. They are then spread on wire netting or other frames made of suitalde metal aud of any 
suitable size. They are then subjected to a process of steaming by live steam, which is injected from 
a steam-boiler into an upright chamber of suitable size, lined with sheet metal, and provided with 
narrow internal fiauges or shelves, upon which rest the wire frames which hold the fisii. The steam 
passes through the closed box and escapes through an opening in the side or end opposite to where it 
is introduced. A door opening outward is also provided for obvious reasons. 
The time consumed in this process is from 10 to 20 minutes, according to the power of the 
steam employed, and may be performed within 2 hours after the fish are first lauded. This steaming 
process has the effect of evaporating the water from the fish in a much more thorough manner than 
by the old process. It has also the effect to prepare the fish for the subsequent liakiug process, and by 
killing any germs in them preventing rapid decomposition, keeping them sweet, and retaining their 
natural flavor. After the steaming process the fish (which remain on the same frames on which they 
were steamed) are subjected to the baking heat of a revolving reel oven, operated by steam or any 
other power, until they are fully cooked or baked. They are then taken from the revolving reel oven, 
cooled a certain time, and jiacked in tin cans, which are supplied with fine oil, mustard, sauces, spices, 
*See Letters Patent No. 299710, dated .Tune 3, 1884. 
tSee the Fishery Industries of the United States, section v, vol. 1, p2). 511-518, aud Bulletin U. S. 
Fish Commission, 1886, pp, 177-179. 
F.C.B., 1898—34 
