770 DAIRY 1. New-Milk Dairies. These, in or near towns, or amidst the dense population of mining and manufacturing districts, are to a large extent kept by persons who, with the aid of their families, undertake the management of from one to a dozen cows, and the delivery of the milk to customers. In our large towns there are also to be found gigantic establishments, in some of which as many as a thousand cows may be seen at one time. In these town dairies the cows are usually purchased when they have newly calved, or are at the point of calving, and they are retained till they cease to give a remunerative quantity of milk. The cows are commonly milked twice a-day, but sometimes thrice, as in the case of those owned by Harvey s Dairy Company, Glasgow. To ensure successful milking, quietness, com fort, and kindly treatment are essential to the animals. The udders and teats should be thoroughly cleansed before the commencement of the operation, The more expedi tious the milker, the better the result. The left arm should be kept firmly pressed against the cow s right leg, in order to protect the pail. Towards the close of the process the hand should reach a little above the teat, and pull down gently upon it at each delivery of the milk, so as com pletely to empty the udder. The milk is conveyed at once to the milk-room, where it is strained, measured, and delivered over to retailers, or to servants of the establishment, by whom it is distributed to the customers. A portion, in some cases half, of the new milk is, however, retained in the dairy for twelve hours. It is then skimmed, and the cream either retailed or made into butter. This business requires the employment of a large capital, and is attended with much risk; but when well managed, is a remunerative one to those engaged in it. Railways have occasioned the introduction of important changes in this branch of dairy business. Instead of the cows being kept in or near cities, where housing, food, and litter are costly, it has become a common practice to keep them on farms near railway stations, and to forward the new milk in suitable vessels twice a-day to retail trades men. It is obviously easier to carry the milk to the place where it is consumed, than first to convey thither the cows and their litter and food, and then to remove to the country the manure which they produce. There can be no doubt, also, that the air and pasturage of the country are of advan tage to the cows. 2. Butter Dairies. Wherever cows are kept some portion of the milk is used for the production of butter. The dairies, however, of extensive districts both in England and Scotland, on account of the attention given to this particular product, are appropriately spoken of as "butter dairies." In the midland and western counties of England, where the breeding of cattle is extensively carried on, the calves, two or three weeks after birth, are fed upon skimmed milk and a gruel of bruised linseed and oatmeal, so that the greater part of the new milk can be converted into butter. When the calves are all weaned, the skim milk is employed in fattening pigs. In many parts of the country buttermilk is much relished by the labouring classes. Wherever churned milk can be readily disposed of, dairy farmers direct their attention chiefly to the produc tion of butter. When new milk is allowed to settle, the fat globules, being lighter than the general mass, gradually rise to the surface in the form of cream. In the process of churning, these globules are broken by the mechanical agitation, aided by the action of the lactic acid which is formed from the sugar of the milk, and the contents cohere to form butter. The usual practice is to allow the cream, whether sepa rated from the milk or not, to stand until it begins to become acid. Butter is made either from cream onlv or from milk and cream together. The best butter is obtained from the cream which rises during the first twelve hours after milking, and the next best by churning the whole milk. In the former case the new milk, after being carefully strained, is poured jnto shallow vessels of glazed earthenware, glass, tinned iron, wood, lead, or zinc, of which the three first-named sorts are the best. Wooden vessels are objectionable from the difficulty of cleaning them thoroughly, and lead and zinc on account of the noxious salts produced by the action of the acid of the milk on the metal. Pans of about 10 quarts capacity, made, without seams, of well-tinned sheet iron, are in common use. Where milk is cooled by means of water the pails are made round, and about 18 inches in depth, or shallow and rectangular, with an ex terior pan for containing the water. The deeper vessels are found to be most suitable in a cold, the shallower in a warm atmosphere. To obtain as much butter from the milk as possible, the first skimming takes place at the end of twenty-four hours, and one or more skim mings are made at further intervals. The cream is stored in jars, which should be kept in a place separate from the milk-room, that the milk in the coolers may not be too early acidulated by the proximity of the sour cream. The latter is either stirred repeatedly, or poured from one vessel to another, to prevent the formation of a tough coat upon it before enough is accumulated for a churning. In large dairies it is usual to churn daily. Three days is as long as the cream can ordinarily be kept for butter of good quality. In the New York butter factories the milk rooms are thoroughly ventilated, and are provided with tanks sunk in the ground, and having a depth of 18 inches of flowing water for cooling the milk whilst it is throwing up its cream. The temperature of the water should be between the limits of 48 and 56" Fahr. The uniform temperature of the cream is said to have a favourable effect on the churning. When a cow has recently calved, her milk is comparatively rich in butter and poor in curd ; but by and by the relative proportions of these constituents are reversed, the cream diminishing and the milk becoming thicker. A very sensible change in the quality usually takes place when a cow becomes pregnant, so that in not a few cases double or treble the ordinary length of time is required to churn the cream, and the butter produced is of inferior quality. If cows are flurried and heated, either by gadding in the pasture, or by being overdriven in bringing them home for milking, their milk becomes peculiarly liable to corrupt, the yield of butter is sensibly lessened, and its quality is impaired. The success of the process of churn ing depends much on the temperature of the cream being nicely regulated. Experiments have shown that a tem perature of from 54 to 59 Fahr., both of the air and of the cream, is the best for churning. The temperature of the cream usually rises about 10 during this process. Advantage is derived from rinsing the churn with cold water in summer and with warm water in winter. The addition to the cream of small quantities of cold or hot water, as the case requires, is also found beneficial. Box or barrel churns are preferred when the cream only is churned, the former being best adapted for small dairies, and the latter for large ones. When the whole milk and cream are churned together, it is indispensable that acidulation and coagulation should first take place, and the churnings should not be at longer intervals than every second day. When the milk is gathered for more than two days some of it is past the proper stage of acidulation at the time of churning, or part of it has not reached that stage, The time required to produce butter from whole milk is much longer than with cream alone, three hours being an average period. The plunge churn is most appreciated for this prac
tice ; and in large dairies it is usually worked by steam,