The Trials of Cream Separators at Boncaster. 499 
At tlie Derby Show of the Society in 1881 three different 
centrifugal cream separators were exhibited, viz. the " Laval; " 
the " Lefeldt," a German machine constructed on the same 
principle as the " Laval," but very cumbrous ; and a Danish 
machine, the " Nielsen-Petersen," which was destined to be a- close 
competitor with the " Laval." The Danish machine differed 
from the others in having an open instead of a closed cylinder, 
and also in the method of skimming ; further, it could deal with 
a larger quantity of milk, and separated G5 gallons per hour. 
Full descriptions and illustrations of both the Danish machine 
and the " Laval" are given in vol. xvii. of the Second Series of 
this Journal (1881), pp. 639, 642-3. 
The first competition among separators was held at tlie 
Reading Show of the Society, in 1882, when a gold medal was 
offered. Originally there were ten entries, but, owing to an 
injunction that had been obtained for infringement of patent, 
only four machines, the exhibits of two different makers and 
representing two distinct principles, actually competed. These 
were, the " Laval " (Swedish), and a machine by Heinr. Petersen, 
known as the " Hamburg Centrifugal Separator." This latter 
is figured and described in the Journal, vol. xviii. (1882), 
p. 621. The Gold Medal was awarded to the " Laval " separator, 
which, showing y^-g- of a horse-power, separated 53 gallons of 
milk in the hour, and left on an average "24 per cent, of butter- 
fat in the skim-milk. The Hamburg machine required of a 
horse-power, and separated 80 gallons in the hour, the skim 
milk containing in one case "26 per cent, and in another -41 per 
cent, of butter-fat. 
At the succeeding Shows of the Society, viz. York 1883, 
Shrewsbury 1884, Presfon 1885, and Norwich 1886, the 
" Laval " (now exhibited by the Dairy Supply Company, and 
capable of separating 60 gallons per hour), and the Danish 
machine of Nielsen-Petersen, manufactured by Burmeister and 
Wain, and exhibited by the Aylesbury Dairy Company, held 
the field alone. 
At the Annual Show of the British Dairy Farmers' Associa- 
tion in October 1884, however, these two machines had come into 
competition, consequent on the offering of a Gold Medal by the 
Association, and at the conclusion the medal was awarded to 
the " Laval " separator. The trial, however, was allowed not to 
be thoroughly satisfactory nor complete ; the time given was too 
brief, and the power required for working was not tested. The 
" Laval " separator left -67 per cent, of fat in the skim-milk, 
the Danish machine "18 per cent, in one case and "32 per cent, 
in another. 
At the Newcastle Show of the Royal Agricultural Society in 
