CIV. ' @, R. COWDERY. 
‘Practically, there has been no difficulty with the machine itself, 
but owing to the extreme hardness of the rails to be milled, a 
considerable amount of trouble has been experienced with the 
cutters. At first the usual solid milling cutter was adopted, but 
owing to the high cost of this form of cutter, and to the fact that 
they would only mill a few rails before they required sharpening, 
and then it was found impossible to get them hard enough, and 
at the same time keep them true, it was decided to give them up. 
A cast iron cutter head was then tried, in which thirty steel 
cutters in a circle of 10” diameter were securely fastened by keys. 
This was a distinct improvement on the previous method, but 
was far from satisfactory, for although the cutters were hardened 
as hard as possible, the very hard rails soon wore them out. ‘The 
experience gained led to an entirely new form of cutter head 
being made. The heads are now in two halves, and the cutters 
are arranged to overlap each other; there are now forty cutters 
in a circle of 10” diameter, or eighty half cutters in a complete 
cutter head. The cutters are plain pieces of steel bevelled off to 
give the cutting edge. They are capable of being adjusted side- 
ways, so that grinding does not spoil them. So far the result of 
the trial with this form of cutter is fairly satisfactory, and when 
some slight alterations are made, we may consider that the 
machine, and the method of doing this class of work, is all that 
could be desired. 
“There are four rails or four fishplates put on the machine at 
one time ; the rate of travel is two feet per hour ; the rails are 
milled two feet up from end, and the fishplates from end to end 
(3 11”). The best result with the new cutters, without sharpen- 
ing, was 50 rails, or 400 feet per cutter head, equalling 1600’ 
with the four sets of cutters.” 
It may be added that it is anticipated the extra cost of pre- 
paring the rails and fishplates will be more than recompensed in 
the ordinary maintenance of the track, to say nothing of the 
lessened wear and tear of the rolling stock. The additional 
_ comfort to the tram travelling public is another important matter. 
