66 BULLETIN 196, U. S. DEPARTMENT OF AGRICULTURE. 
utes. Some experiments were made on using temperatures above boiling for a shorter 
period, but as the temperature rises above 220° F. the color becomes darker. 
The canning of sweet potatoes is still in an experimental state, as brokers and job-— 
bers have demanded an appearance which has been attained for the most part by- 
overfilling and which is prone to produce springers. These are sound and whole- 
some as food, but the can presents an appearance which makes it unmerchantable 
and, unlike products containing liquid, a part can not be withdrawn and the can 
resealed. 
TOMATOES (LYCOPERSICON ESCULENTUM). 
The time is easily within the memory of many persons when tomatoes were thought 
to be poisonous. A few persons in the Eastern States used them 70 years ago, but 
they did not become common until a much later period. In the West the prejudice 
against them persisted until less than 40 years ago. The first record of canning toma- 
toes is that of the work done by Harrison W. Christy in 1847 at Jamesburg, N. J. 
Tomatoes are now used in enormous quantities in the fresh state and head the list 
of all vegetables as a canned product. Thousands of bushels are also used in the 
manufacture of ketchups, chili sauce, and soups. The tomato is produced over a 
larger part of the United States than any other vegetable. It may be handled with 
few and simple appliances, and may therefore be canned in the home and in small 
factories where little capital is required, as well as in the large factories. 
The development of a tomato suitable for canning purposes has been a specialty 
in itself. For canning the fruit should be moderately large, smooth, so that it will 
peel readily, ripened evenly to the stem, of a clear, red color, and having a large 
proportion of solid meat of good flavor. Varieties which ripen unevenly or are irregu- 
lar in outline are difficult to peel and the percentage of waste is too high. Tomatoes 
which are yellow or purple do not have an attractive appearance on opening, and 
those with excessive seed cells or which are soft and watery will give the can the 
appearance of being slack filled or packed with water. A good pack is therefore 
dependent upon having a variety possessing the right qualities. The canner can not 
accept tomatoes of a half dozen or more varieties and get good results. He must there- 
fore specify the variety grown or furnish the plants for his growers. The production 
of plants in hotbeds and cold frames to supply several hundred acres is of itself a’ 
very large task. The plants are grown in the field, the same as other crops, and a 
single large cannery will use the product of 1,000 acres. One ketchup manufacturer 
takes the entire product from more than 5,000 acres. A fair yield is 5 tons of fruit 
for an acre, but good cultivation and fertilization sometimes brings this up to 20 tons 
or more. Thirty-three bushels weigh about 1 ton. 
At harvest time the fruit must be picked every day, or every other day, in order 
to insure collecting it when it is in its prime—just ripe, without green butts, and not 
overripe. It is preferable that the tomatoes be put in crates which are wide and 
flat rather than deep, and which will hold not more than a bushel. They can be 
delivered to the factory in better condition in the flat crates than in the deep ones 
or in baskets, as the fruit will crush if piled in too many layers. Arrival in good con- 
dition lessens the time required for peeling as well as the loss in parts cut away. The 
tomatoes should be delivered to the factory promptly, as deterioration begins soon 
upon sianding. is 
When the tomatoes are delivered at the factory they are weighed, and inspection 
should be made of each load. One crate is taken out at random and dumped into a 
tank of water. All defective fruit can be detected at once, picked out, weighed 
separately, and the load docked accordingly. Rotten fruit can not be used and 
green fruit must be held to ripen. The separation at the factory entails extra expense 
in the inspection and sorting. The rotten fruit should not have been picked and 
