ness of the meats, varying from 15 minutes, with meats very dry, to 45 minutes, with green or damp meats. The steam-pressure in the jackets will depend upon the same conditions with regard to seed and upon the length of time in which it is desired to complete the operation, and may vary from 40 to 100 pounds. With very dry seed it is necessary to add moisture to the meats to assist in cooking. The direct injection of steam alone usually suffices for this purpose. Green seed as a rule cooks very easily and frequently with such rapid evaporation of moisture that it is necessary to raise the cover of the cooker to allow the steam to escape before the meats are brought to the proper consistency for pressing. Heating should not be too rapid to secure the best results, viz., bright, compact cake and light-colored oil. If cooked too much the cake is brittle; if cooked too little whereby an undue amount of moisture is retained, the meats ooze out of the press-box, injuring the press-cloth and producing a "leathery" cake. Hasty cooking tends to make the oil too red and the cake too hard.

The tendency of the flaky meats to agglomerate in small lumps or "water-balls" under the action of the stirrers, may be corrected by subjecting the crushed meats to the action of a beater, whereby they are reduced to a meal. Heat penetrates the interior of the "ball" with difficulty, with the result that the action on the presscloth of meats containing them is the same as that of under-cooked

meats.

With seed of uniform quality, which uniformity may frequently be maintained for periods of several days or a week or longer, the steam-pressure may be kept constant and the time of cooking varied to suit conditions of the meats; or the time of cooking may be kept constant and the steam-pressure varied according to the moisturecontent of the meats. The temperature of cooking does not, as a rule, exceed 220° Fahr.

Owing to the varying character of cottonseed with respect to its moisture-content, a system of the strictest regularity at the cookers, with respect to time allowed for each batch of meats, steam-pressure, etc., becomes impossible. The entire responsibility of successful operation rests upon the "cook." His judgment and experience must determine the nature of the treatment followed, and with him

must reside the responsibility for the successful results of his work. The right temperature, uniform distribution of the heat, and a thor

FIG. 33.-Improved Automatic Steam Cake-formei

oughly homogeneous mixture of the mass of meats are prime essentials of proper cooking.

The sub-heater is similar in construction and manipulation to the cooking-heaters. It is placed below the bottom level of the

cooking-heaters and receives the cooked meats from them by conveyor. Formerly the cooked meats were delivered directly to the cake-former but not with entirely satisfactory results, as the last portion of the charge remaining in the cooker was often cooked too much. By the use of the sub-heater, which is now general, the entire charge when cooked can be delivered by conveyor to the subheater and there retained without decrease of temperature until all is put through the cake-former. When the process is completed in the cooking-heater and the meats delivered to the sub-heater, it is essential that proper thermal conditions be maintained there.

Cake-forming. The cake-former, shown in its relative position to the heaters in Figs. 30, 31, and 32, is illustrated separately in Fig. 33. Its object is to shape or form the cooked meats into compressed cakes of uniform size and weight before subjecting them to pressure. In the steam-former shown in Figs. 30 and 33, the ram is 18 inches in diameter and is provided with an automatic cushioning device for the drop or return stroke. The carriage runs beneath the outlet of the sub-heater, from which is delivered a uniform quantity of cooked meats. On the top of the ram is laid the press-cloth, onto which the carriage discharges its quantum of cooked meats. Under steam-pressure the ram ascends, subjecting the whole to the desired pressure. The press-cloth is then folded over the cake, which is carried on a tray or plate to the press and inserted in an empty compartment. The former is ample for four presses. Great care should be taken that the cakes be made uniform in thickness and density, and be properly wrapped, so that - pressure is exerted uniformly, otherwise loss is suffered through injury to press-cloths.

There are various types of formers. The ram may be operated by direct steam-pressure as described, hydraulic pressure, compressed air, or driven by belt.

Transferring cooked meats from the sub-heater to the former is likewise effected in a number of ways.

Van Winkle's Modification of the Extraction Process.-It is naturally to be desired that the maximum yield of oil be obtained, and many patents for processes looking to a closer approximation of the theoretical yield have been recorded. The tendency of all manufac

turing is toward simplicity of operation consistent with economy. Closer approximations to theoretical yield from raw material in any industry may involve greater expense, either in direct outlay or in inconvenience or added complexity of operation, than there is economy secured. Experience with new ideas in the varying conditions of practical work can alone determine their value.

Van Winkle's patent relates to an improvement in the process of extracting oil from cottonseed, whereby the yield of oil is claimed to be increased and the operation rendered cheaper, simpler, and more effective. In Fig. 34 is represented diagrammatically an apparatus for carrying out the process.

In this apparatus, a represents the huller, and b the conveyor, which delivers the broken seed from the huller to the elevator c, by which elevator they are delivered to the separator d, the hulls being discharged at the end of the machine, while the meats fall down into the conveyor e, from whence they pass through the chute ƒ to the elevator g. The elevator g delivers them to the crushing-rolls m. This conveyor h is surrounded by a steam-jacket i, into which steam is delivered through a pipe j, the purpose of this steam-jacket being to heat the meats during their passage through the conveyor h. A steam-pipe k, provided with a valve l, connects the steam-pipe j with the conveyor h. This is for the purpose of moistening the meats if moisture is necessary. This conveyor h, with its steamjacket and steam-pipes connected to the conveyor and jacket, is what may be called a "tempering device," whereby the meats are prepared for the crushing operation. If the cottonseed is fresh, no moisture is needed. If, however, it is old and dry the subsequent operation will be much facilitated by moistening it before it is crushed. If the seed is very fresh, the meats are soft and sticky, containing in some instances too much moisture. This objection is also overcome by means of the tempering device, some of the surplus moisture being dried out and the meats thereby brought to the right consistency for the crushing. The meats after being crushed by the train of crushing-rolls m fall into a conveyor n, which delivers them into an elevator o, which delivers them in turn into a conveyor p, located above the cooker q. This cooker is supplied with steam by means of the pipe r, which is connected with