Low temperature, as we know from household practices, is used to inhibit decay, which it does by slowing bacterial growth and enzym action. When chickens are alive their temperature is 103° F. This must be reduced to 32° F. or less before the birds can be packed for long hauls in refrigerator cars.

The time required to chill the fowl is usually about 24 hours, and the packer must be sure that the viscera, as well as the skin and flesh, are free from heat before the birds leave the chill room. It is the failure to observe this requirement that is responsible for much of the bad-conditioned poultry in our markets. The range of temperature permitted, too, is small. Below 30° F. the flesh is frosted; above 35° F. decay proceeds too rapidly to permit of long hauls to distant markets and a routine of marketing such as our urban life now requires. Of course, the birds can be frozen hard after they are chilled, and so shipped, and this is a very excellent plan, especially if the haul is across a hot country.

GRADING AND PACKING.

Having removed the natural heat from the dressed fowls, the next step in their preparation is to grade and pack in suitable containers for shipment. This operation should be performed in a room having a temperature of 30° F. and in this room the packed boxes may remain for several days while awaiting shipment.

No longer does the packer thrust old cocks, broiling chickens, and fowls indiscriminately into the big sugar barrel, pressing down the birds in his endeavor to pack tightly and so bruising flesh and tearing skins. Such a procedure prevents good keeping; therefore the shipper, far from his market, must not only avoid it but he must use a package that allows the birds to stay in good condition the maximum length of time. With this end in view, as well as to enable his customers to see at a glance the quality of his product, he has adopted wooden boxes, holding only 12 birds each. He also takes care that each bird of the 12 is an exact match for the other 11, both in weight and quality, and when he has a brand on the box and a reputation in the market, he even matches the color of the skins, that the package may present an attractive appearance. Such exactness involves experience and knowledge in grading the birds, and is by no means a simple operation. Plate XVII shows the interior of a packing room with graders and packers at work. Natural light falls on the rack from which the birds are being removed; each dozen as selected are weighed on the track scale and the weight stamped on the box into which the packer puts them. The boxes are lined with parchment paper to protect the skins and to prevent evaporation, and sometimes, especially if long storage is contemplated, each bird is separately wrapped.

73029°-YBK 1912- -19

Plate XVIII shows the appearance of these boxes of chickens. Broilers are breast up, and there is but one layer in the box; roasters and fowls are packed on their sides, and two layers are used. The boxes of broilers weigh from 15 to 24 pounds; roasters and fowls may run 60 pounds to the box. The ordinary barrel of poultry weighs 250 pounds or more. When one considers the delicate character of the skin and flesh of a chicken and the pressure that the poultry in a heavy package exerts upon itself, it is easy to see what advantages in the way of good carrying apply to the small box.

For very high-grade poultry the carton holding one roasting or two broiling chickens is being used to a limited degree (Pl. XIX). Like all individual wrappers put on at the source of production, it tends to keep the bird clean and sound skinned. It also insures to the housewife a package that has not been mauled by prospective customers nor soaked in water by the retailer to freshen up a driedout bird, or perhaps to remove the odors of beginning decay. When high-grade poultry is to be kept from the season of production to the season of scarcity, as is necessary to feed this great country, the carton pack is highly desirable. The drying out of the flesh in the low temperatures of the cold store is very largely prevented and, what is even more desirable, the unbroken package can be sent hard frozen to the consumer. As the consumer becomes better informed on the subject of food supplies and their handling the packers will mark the cartons with the date of killing, as well as the brand of goods. Thus the purchaser will see that the bird has been killed during the season when the quality is highest-broilers before December and roasters between September and January-and that they have not been held in storage more than 12 months. The packer of high-class goods is now more than willing to put such information on his labels; the warehouseman desires it; the wholesaler wants such information; but the retailer can not risk giving the true story to the consumer because the prevailing ignorance would translate the truth into undesirability, and the purchaser would go elsewhere to purchase the same grade of goods, but accompanied by the verbal statement of" strictly fresh and nearby." The consumer does not realize when he clamors for true labels on foodstuffs that his own ignorance and prejudice are the greatest bars to the obtaining of his wishes.

SHIPPING METHODS.

But to return to the boxed poultry that we left in the refrigerated packing room waiting for its long journey to the consumer. How must that journey be made to insure good order on arrival? The answer used to be "speed," because the time that the produce would keep was so short under even the best of prevailing conditions that the whole course of marketing must needs be rushed. Now the

reply is, good handling and refrigeration, from start to finish; refrigeration evenly and constantly maintained, because cold is a great discourager of those all-pervading and ever wide-awake forms of plant life, bacteria and molds, without which we do not have decay.

To maintain refrigeration between the far-distant source of supply and the consuming center, we have developed a system of refrigerated carriers in connection with our railroads, and we are as dependent upon them for our food supplies as is England upon her ships. The traveling public everywhere is familiar with the appearance of the outside of the freight car which bears the word "refrigerator," as well as the initials of its line, but few of the many thousands who depend on those cars for their daily supply of foodstuffs know how they are constructed and made efficient for the work which they are to do.

Ice is used to produce low temperatures, and when below 40° F. is required salt is mixed with the crushed ice. A compartment is built across each end of the car to hold the ice, and openings above and below, into the body of the car, permit circulation and consequent cooling of the air of the car. Plate XX shows the procedure of icing and salting. Rock salt is contained in the barrel which lies on the roof of the car. The hatches through which the ice and salt are put into the bunkers are also shown. In some places ice crushers are used instead of man power, which greatly hastens the icing process.

In order to keep the heat of the atmosphere from penetrating the car and so disseminating the cold produced by the refrigerant, insulation must be used in its construction. The modern refrigerator car is rapidly becoming a chill room on wheels, and it must be that if it is to serve the public to its satisfaction and to the financial profit of the railroads as well. During the long hauls in the United States the same car, with its unbroken load, must traverse the heat of deserts and the cold of high mountains, or go from the warm southland to Alaskan snows. It may be that the load carried must not vary in temperature more than 5° F., in which case ice is used in some parts of the journey and stoves in others.

Our chickens, however, seldom become too cold. It is heat that we must guard against when they are shipped; therefore the careful packer will ask the railroad to set the refrigerator car on his siding at least 24 hours before he expects to load, for no packer who works to prevent decay ever loads his poultry in a car having a high temperature or hauls chilled goods in wagons. Then he will examine the car to see that when the doors are closed not a ray of light enters, because that would mean inefficiency of insulation. He looks also to see that drain pipes are working and the general repair good, and, finally, after the car has been iced and

salted for at least 24 hours, he takes the temperature about 4 feet from the floor midway between the doors. If it is below 40° F., he may load his chilled birds with safety. Plate XXI shows the loading of a car with mixed boxes and barrels of poultry. The packages bearing tags are to be examined by the United States Department of Agriculture when the goods reach their destination and their condition noted. The small iron-bound chest contains a thermograph which registers the temperature of the car during transit. One tagged barrel contains dry-packed, the other ice-packed poultry. The latter is the barrel having a big lump of ice under the burlap covering. This experimental shipment was made to determine the relative keeping time of wet and dry packed birds and also to study the question of the height of the load in the car. The car shown in the photograph is loaded too high. About 4 feet is much better. A great many experimental shipments of poultry have been made by the Food Research Laboratory to learn the best available way to conduct every phase of the handling, and it is on the basis of this experimental work that the statements in the present article are founded.

The loading of a car containing 20,000 pounds of poultry-that is, the car lot of the West-can be accomplished in 30 minutes if the work is well planned. It should be done as expeditiously as possible to prevent a rise in the temperature of the car. Even with prompt loading it is well to have a heavy canvas curtain hung in the door of the car to keep the outside air from entering. A better plan still is to have a door in the packing room which opens on the loading platform, and then connect the car and the packing room by means of a canvas corridor.

Having loaded the car and again observed the temperature, that the packer may know under just what conditions his goods start on their long journey, the doors are closed and sealed. The railroad agent knows the perishable character of the freight, and he issues instructions to add ice and salt while en route that low temperatures may be maintained. Or the packer himself may designate when and how he wants his car iced. When the doors are closed they should remain closed until the market is reached. If the packer has dressed and chilled the birds properly, if the refrigerator car is well insulated and built, if ice and salt are added as needed during the haul, the load is just as sure to reach the market a thousand miles away-that is, about five or six days as reckoned by time-in good condition as is a carload of cast iron. After the chickens reach the market they have still to go through the hands of the commission man, the retailer, and, perhaps, the storage warehouse. But that is another story.

SOME RESULTS OBTAINED IN STUDYING RIPENING BANANAS WITH THE RESPIRATION CALORIMETER.

By C. F. LANGWORTHY and R. D. MILNER,

Nutrition Investigations, Office of Experiment Stations.

INTRODUCTION.

Various agricultural products that were formerly available to the consumer only in rather limited areas and in quite restricted periods at certain definite seasons, may now be had almost everywhere and at practically all seasons of the year. This is due to modern methods of production and distribution. For many crops the kind of attention paid to details of growing, transportation, and marketing depends largely upon the market for which they are intended. The condition to which fruit, for instance, may be allowed to ripen depends upon the distance to which it is to be transported and the length of time it is to be kept before sale. Some fruit, for example the apple, may be allowed to ripen almost fully on the tree, and if proper attention is paid to handling and storage, may be kept for relatively long periods, and even with improvement of the quality of some varieties. The peach may retain its color and texture and appearance for a considerable time in storage, but its flavor can not be retained. Soft fruits like the strawberry can be kept for only a very short time without deterioration and decay. On the other hand, such fruits as the banana may be picked before the ripening process has begun, transported long distances, and ripened, under favorable conditions, according to the market demand.

PROGRESS OF RIPENING.

The phases of fruit ripening are familiar and easy to follow. Development to full size, the gradual softening of tissue, the change in color (usually from green to red, yellow, purple, or blue), the change in flavor from acid, bitter, or astringent to mild, sweet, or bland, and the development of aroma are the principal steps. When fruit is fully ripened, the processes which have been going on do not cease, but continue with loss of quality. The texture grows too soft,