WALLEM ON AMERICAN FISHEEIES. 95 



named method I shall, therefore, treat of first, also for the reason that 

 it luay possibly be interesting to the public. 



The great pork-slaughtering houses operate chiefly in winter; the 

 summer killing is regarded as of an inferior quality (judging from the 

 recommendatory advertisement, "winter-cured" American pork). The 

 reason is, that heat will i>revent, in a greater or less degree, the successful 

 salting of pork ; in the cold of winter one may be more certain that the 

 pork will be put in salt sufficiently early, or that the air will not iirlluence 

 the flesh before the salt has begun to operate. During a visit which I 

 paid to a pork-butchery I convinced myself of the significance of refrig- 

 eration for the trade. The body of the hog, as soon as the animal is 

 killed, is thrown into a large scalding-trough filled with hot water, where 

 it remains some minutes, to be scalded, or sufiiciently long for the whole 

 carcass to become so thoroughly hot that it takes a long time before it 

 is cold enough for salting and packing. It is important, now, to shorten 

 this interval, and also to prevent any hurtful influence from the action 

 of the air. In winter this is not so dangerous. In summer or in warm 

 weather it is hurtful. A sudden cooliug-ofi' by putting the pork in ice, 

 it is thought, will injure its flavor; and even a natural cooling-off in 

 wintry air is not to be recommended. It is important, thei'efore, to 

 devise a method by which refrigeration could proceed to a proper length 

 of time and uniformly, independent of the weather, and in such a way 

 that the right point of time for salting could be determined with safety. 

 They have here, among other things, constructed for a refrigerator a 

 large box with a blowing contrivance or pump. Inside of this box, large 

 enough to hold a small drove of hogs, the carcass is hung up ; thereupon 

 the air-pump is set in motion, first to pump out the warm air given oif 

 by the carcass, and then to blow more and more cool air in until the air 

 corresponds with cold water, and cold air from an ice-chamber follows. 

 The current of air travels constantly the same way, flowing along the 

 ceiling or the upper side of the box towards one end, from which it goes 

 backward along the bottom to the other end, when it carries the heat 

 from the carcass up and out. When the cooling is somewhat advanced, 

 they do not allow the current of air to escape into the outside air, but 

 into an ice-chamber, and thereby it becomes colder and colder until it is 

 everywhere uniform and the cooling of the carcass is finished. To give 

 the current of air greater cold, ice is mixed in the ice-room with salt in 

 such proportion as will give out the degree of cold desired. 



This last part of the refrigeration forms the basis of the method of 

 treating fresh meat in its transportation over the Atlantic in steamers. 

 The meat is brought on board soon after killing, and is quickly cooled 

 off and sewed in muslin; thereupon it is hung up in the inclosure 

 arranged in the room for transportation. It is important now to main- 

 tain a low temperature until the vessel reaches the European port. How 

 this is accomplished I shall seek to explain as I describe the refrigera- 

 tors which I saw in the American steamer which carried me across. 



