126 SCIENCE AND PRACTICE OF DAIRYING. 



and their own weight, and must on that account be very strong. 

 The first and most important quality of every separator-drum is its 

 strength. 



61. Milk-separators at Present in Use. Since 1877, the construc- 

 tion of separators has been improved from year to year. While 

 the usefulness of separators has far exceeded the most confident 

 expectations at first entertained, it cannot be asserted that we have 

 yet reached their limits of capability; indeed, it would appear as if we 

 had now reached a point from which a fresh start towards further 

 improvement could be made. Not taking into account some of the 

 separators of antiquated construction, and the separators which, 

 although no longer made, are still in use in various places, we find 

 that there are only five different kinds of separators for power-use, 

 and six for hand-use, employed in German dairies, regarding which 

 the following details may be given. 



62. The Lefeldt Separator. In the manufactory of Lefeldt and 

 Lentsch at Schoningen, in the Grand Duchy of Brunswick, seven 

 separators of different sizes and construction are made at present, 

 of which three are worked by steam, one by a winch, and three by 

 hand. Separators for hand-use were first constructed in 1877. The 

 separators worked by power have undergone many changes in their 

 construction from the introduction of the first in 1877 to the one at 

 present in use. From the end of 1879 they have been constructed 

 for continuous use. They are sold under a guarantee, and can be 

 unreservedly recommended. The separators worked by power 

 (fig. 29) require good, pure lubricating oil. 



Of exactly similar construction as at present made, only of 

 different sizes, are the three separators, Nos. 0, 1, and 2, for steam- 

 use. At present a new separator is being made in this manufactory, 

 which is to be called the " multiplex ". The three separators, Nos. 

 0, 1, and 2, have cylindrical upright drums closed above and open 

 below, constructed with Siemens-Martin steel, with four continuous 

 flanges, and with a thickness in the case of (0) and (1) of I'l centi- 

 metres, and in the case of (2) of 1*4 centimetres. The largest 

 internal diameter measures in the case of (0) and (1) 30, and in the 

 case of (2) 40 centimetres. The first-mentioned two have an under 

 opening of 20 centimetres, and the last of 30 centimetres broad. 

 The milk coming in, runs first into a bowl-shaped aperture in the 

 upper portion of the drum, and is conducted hence by means of 



