Swiss cheeses are made in two styles, the "round" or drum and the "block" or rectangular forms, each of which has its advantages. For the round style, which is most commonly made, the forms for hooping are of metal or of elm wood, and consist of strips of a given width, generally six inches, but of an undetermined length. These strips are then made into a circle and held by a cord, which is easily lengthened or shortened, thus varying the diameter of the hoop. Besides these hoops, cheese boards or followers are needed. These are heavy circular boards, of a size to fit that of the cheese generally made, and are banded with iron around the edge and cross-braced on the bottom for rigidity. The small tools of the factory consist of knives to cut the curd, and of a "Swiss harp" or other similar tool to stir the curd. Many clean bandages are also needed, and a kettle brake. +267. The milk.+--Swiss cheese requires clean sweet milk. Dirt, high acid and infections with undesirable bacteria involve difficulties of manufacture and frequent losses of cheese. One common practice rejects milk if it shows acidity above 0.15 per cent. To secure milk in this condition, factories are small and located so close to the producing farms as to secure 1000 to 3000 pounds of milk delivered warm from the cow twice a day. The cheese is made twice daily from this fresh milk. If, however, milk is properly cared for, it is possible to mix night's and morning's milk without bad results. In fact, in working experimentally with high grade milk and taking precautions against loss of fat, it has been necessary to skim (separate) part of the milk, thus reducing the ratio of fat to casein. Analysis of good Swiss cheeses shows that the desired texture is more uniformly obtained with milk in which the fat is less than the normal ratio. This assumes that the manufacturing loss is kept down so that the fat removed offsets the extra loss from curd-breaking. +268. Rennet extract.+--Most Swiss cheese-makers prefer to make their own rennet extract from the stomach. This results in a product which is not uniform in strength and so requires good judgment to secure the desired coagulation in the allotted time. Some cheese-makers roll fifteen to twenty well salted calves' stomachs together and dry them. From this they cut off a definite amount each day to be soaked for twenty-four hours in two to five quarts of whey at 86° F. Four quarts of this solution added to 2000 pounds of milk at 90° F. should produce a curd ready for cutting in twenty to thirty minutes. +269. Starter.+--Makers do not agree as to the use of "starters" for Swiss cheese. Those opposed to such use say that a starter will give the cheese a decided Cheddar flavor, while those in favor of it state that it will control undesirable fermentations, and that, with the use of a starter, it is possible to make Swiss cheese throughout the year, and have uniform success.