and Machinery at Bristol. 
139 
barrel, slightly conical in shape, hung from central pivots, so 
as to admit of being easily turned upside down, if required for 
emptying and cleaning, and was supported on a wood frame. A 
wood spindle, armed with two thin wings, or strips of wood, 
3 inches wide, runs on a central boss in the middle of the churn ; 
power is communicated by bevel gear from a counter shaft, 
supported on the top of the frame, to which the upper end of 
the spindle is connected. 
Before distributing the milk to the various competitors on the 
morning of the 9th, the samples were taken by Dr. Voelcker, both 
from the surface and bottom of the vat.* We were thoroughly 
* The milk used in the experimental trials had a specific gravity of 1*031 at 
a temperature of 66° Fahr. On standing, it threw up 11 per cent, of cream by 
measure. 
The milk brought into the yard on the evening of the 8th of July was received 
into a large vat. Before distributing the milk to the various competitors on the 
morning of the 9tb, it was well stirn d up, but in the short space of a quarter of 
au hour a partial separation of the cream took place, as will be seen by the fol- 
lowing trials. 
A sample of milk taken from the top of the vat, in the course of 12 hours threw 
up 15 per cent, of cream, by measure. Temperature of milk, 63° Fahr. Another 
sample taken from the bottom of the same vat, in the same period, and at the 
same temperature, produced only 4 per cent, of cream, by measure. 
It is of the highest importance to bear in mind in trials on the production of 
butter by different churns, that a partial separation of cream rapidly takes place 
in milk, and it is to be feared that the great diflierences in the quantities of butter 
produced iu different churns in recorded trials from a given quantity of milk are 
mainly due to this som'ce of error, which the Judges in the Bristol trials have 
overcome by not giving each competitor his full quantum at once, but by doling 
out the milk in two-gallon lots all round, continuing to well stir the milk in the 
large vat all the time. As soon as all the competitors had obtained tlieir allowance, 
test samples were taken after a few turns of each churn, to secure a perfectly 
uniform condition of the mUk, and these samples were set aside in separate cream- 
gauges, at 12.30 P.M. on the 9th ; and at the same time the temperature of the milk 
in each churn was taken. At 9 o'clock on the morning of the lOtb, the per- 
centage of cream was registered with the following results : — 
Milk used in Churning on the 9th of July, 1878. 
Cliurn. 
Percentage of 
Cream on the 10th 
July. 
Temper.iture of 11 ilk 
on the 9 th, before 
Churning. 
Number. 
Per cent. 
o 
2116 
7 
62 
2018 
7 
64J 
2022 
7 
64 
1904 
7 
64 1 
2347 
7 
62 
1974 
7i 
64^ 
1813 
7 
65 
1953 
n 
65 
2088 
7 
64 
6346 
7 
64 
4023 
7 
64 
The result, it wiU be seen, was most satisfactory ; the greatest variation in the 
