The Trials of Milking Machines , 1913. , 241 
Sub-section (h). Ease and thoroughness of cleaning. This 
is most important as upon it largely depends the purity of the 
milk. During the trials it was specially stipulated that only 
cold water, hot water, and steam should be used in cleaning any 
part of the machine to which the milk had access. This was 
at the request of the bacteriologists. Doubtless the use of strong 
antiseptics would have been most prejudicial to their work. 
Arising from this sub-section, the question of rubber tubes 
conveying milk should be considered. As far as possible this 
practice should be condemned, for several reasons, the most 
important of which is the fact that it is practically impos- 
sible to prevent the presence of bacteria on a surface such as 
rubber presents. In other words, it is most difficult to clean 
thoroughly. Another point against the use of rubber tubes is 
the fact that they are very apt to perish and crack where they 
are continually being bent over as is done in the case of placing 
the cups on the teats in most machines using a vacuum. 
Sub-section (k). This will be dealt with in the description 
of each individual machine. 
In giving a short description of each machine we propose to 
first take the one which the Judges selected as being the best 
machine which was presented for trial. 
Mjolkningsmaskin Omega. First prize of 25 1. and gold 
medal. — It will be noticed on referring to the illustration of 
that part of the Omega machine which is essentially “ cow 
borne,” that it consists of four main parts : the teat cups, the 
conduits, the pulsator, and the receptacle. It will also be seen 
that these four parts are combined in one unit which is attached 
to the cow by means of web straps, so that the weight of the 
unit is supported entirely by the cow, but unlike the majority 
of machines the milk ducts are made of celluloid, are trans- 
parent, and very tough, the inner surface very nearly approaches 
the smoothness of glass, and so are quite easily cleaned. 
Before leaving the subject of these tubes it may be of 
interest to know that having misgivings concerning their 
strength under the different ordeals to which they were liable 
to be put during the process of cleaning, as well as in use in 
the byre, the exhibitor was asked if he would allow us to test 
one of them to destruction short of burning it. This was 
readily agreed to, so we first of all tried the bending test cold ; 
with considerable force we were able to partially buckle the tube. 
This was easily repaired by placing the tube in boiling water 
when it became sufficiently soft to restore it to its original 
form by a gentle pressure of the thumb and fingers. We then 
subjected the tube to the heat of steam at 60 lb. per square 
inch, which amounts to 292*7° F. It became soft but kept its 
