The advent of the twentieth century finds the dairy industry of the United States established upon a plane far above the simple and crude domestic art of three or four generations ago. The milch cow itself, upon which the whole business rests, is more of a machine than a natural product. The animal has been so bred and developed to a special purpose, that instead of the former short milking period, almost limited to the pasture season, it yields a comparatively even flow of milk during ten or eleven months in every twelve; and if desired, the herd produces as much in winter as in summer. It is not unusual for cows to give ten or twelve times their own weight of milk during a year. And the quality has been so improved that the milk of many a good dairy cow will produce as much butter in a week as could be made from three or four average cows of the olden time. Instead of a few homely and inconvenient implements for use in the laborious duties of the dairy, generally devolving upon the women of the farm, perfected appliances skillfully devised to accomplish their object and lighten labor are provided all along the way. The factory system of coöperative or concentrated manufacture has so far taken the place of home dairying, that in entire States the cheese vat or press is as rare as the hand-loom, and in many counties it is as hard to find a farm churn as a spinning-wheel. Long rows of shining tin pans are no longer seen adorning rural dooryards, as one drives along country roads; but in their place may be found the bright faces of “the women-folks,” who rejoice over the revolution of modern dairying. [Illustration: MILK TESTER (OPEN).]