102 



favour, and another separator manufactured by Koefoed and Hauberg 

 is used to a considerable extent. 



The vessels in which the cream is set to ferment are mostly wooden 

 barrels, made of oak, or in some places large tin cans. Sometimes the 

 latter are fitted into a wooden tub, with the object of maintaining an 

 even temperature. The receiving tank into which the milk is poured 

 after it has been received and weighed, is sometimes of wood, and in 

 other places made of heavy tin. It is always placed on a high platform, 

 bo that the milk can flow by gravitation to the separators. The milk 

 should be raised to a temperature of upwards of 75° Fah., and it is ne- 

 cessary there to heat it by steam, by passing through a jacketed tin or 

 copper vessel placed inside another so that the space between them is 

 filled with steam, while an "agitator" revolves slowly in the milk to 

 warm it evenly. To regulate the inflow of the milk into the separator 

 Professor Fjord invented a regulating funnel. Others put a "swimmer" 

 in the funnel, which rises up against the end of the discharge pipe, par- 

 tially closing it if the milk runs too fast. The cream from the separator 

 runs from a suspended vessel through the steriliser to the cooler. Pro- 

 fessor Fjord's steriliser or pasteurising apparatus is a copper cylinder, 

 coveied with tin, fitted steam-tight into a somewhat larger vessel of 

 copper or galvanised iron, and then "lagged" outside with wood to pre- 

 vent cooling. The steam passes direct from the boiler between the two 

 vessels, and out by a pipe at the bottom. The milk or cream enters the 

 vessel, which contains an agitator, from below and flows out near the 

 top, where a thermometer can be inserted. The temperature must be 

 from 170° to 180° Fah., and is intended to kill the microbes or bacte- 

 ria. The steriliser is used for sweet, or for skim milk, or for cream. In 

 nearly b11 cases where the sweet milk was sterilised before separation 

 Mr. Gfeorgeson found that the skim milk was again sterilised before 

 leaving the separator, as if then fed to the calves it was claimtd that all 

 possible danger of infection with tuberculosis was avoided. 



The cream, after passing through the separator and steriliser, must 

 next be cooled. It is poured into a hopper on top of the cooler. This is 

 either a round or square apparatus of corrugated metal containing a 

 worm or thin zigzag pipe, into which cold water enters from below, 

 passes through the pipe, and is discharged again below. The water is 

 supplied from a vessel which contains broken ice, placed high enough to 

 force the cold water through the pipe. The cream, on running in a thin 

 stream over the corrugated metal, is cooled, so that a cooler 3ft. high 

 may cool 5,000 lb. of milk per hour from 180° Fah. to about 3 / Fah. 

 above the temperature of the ice water. It requires 30 lb. of ice to every 

 100 lb. of milk to reduce the temperature to at least 41° Fah. (The dif- 

 ficulty in Australia may be to obtain artificial ice at a low price. In 

 Denmark they store ice in winter near to the dairy. Well water, former- 

 ly used in Denmark, cannot lower tbe temperature sufficiently. The dif- 

 ficulty might, perhaps, be overcome by placing water beforehand in a 

 freezing chamber, if such is attached to the dairy.) The sterilisation and 

 the cooling can, however, be done without the aid of the steriliser and 

 cooler, but it involves more labour. The cream must be put into tall 

 cans, which have first been thoroughly cleansed by washing in mild 

 lye, or by the addition of soda and a solution of lime to the water, and 

 thereafter pouring scalding water or a jet of steam into them. After 



