PROCEEDINGS OF SECTION H. 361 
by a brick buttress built up from ground level. A small plat- 
form carried out on brackets will give access all round this 
nler. 
On top of the tower a brick pier will be placed, on which a 
theodolite suited for geodetic work will be placed. The alti- 
tude above sea level will be 200 ft., and a view of all surround- 
ing geodetic stations, as well as the sea horizon, can be obtained. 
At this pier the horizontal circles of theodolites can be tested 
by measuring angles of known magnitude. 
A clear space of 2 ft. square passes from the top. of the tower 
to the floor of the chain standard, a height of 75 ft. This 
will be available for plumbing work in connection with the 
mining survey work, the chain standard passage being darkened, 
and used as a drive. ° 
8—ON THE BALANCING OF LOCOMOTIVE ENGINES. 
By Proressor W. C. Kernot, M.A., M.C.E 
Ix the year 1893 it was the writer’s duty to preside over an 
inquiry relating to the administration of the Locomotive Branch 
of the Railway Department, in the course of which much evi- 
dence was given to the effect that certain locomotives of recent 
design and construction had proved unsatisfactory, being de- 
ficient in point of speed, causing great discomfort to the drivers 
and firemen, and damaging the permanent way by fracturing 
rails and otherwise. An examination of these engines, the 
majority of which were of the six wheels coupled inside cylinder 
class, showed that there were no balance weights whatever, the 
designer having apparently considered the outside coupling 
rods and their crank pins and bosses a sufficient balance to the 
inside cranks and their connections, a view that is taken by at 
least one recent English writer on the subject. As the engines 
presented no other abnormal feature it appeared to the writer 
that possibly imperfect balancing might account for the de- 
fects complained of. He therefore obtained full data as 
to dimensions and weight of moving parts, and proceeded 
to compute the magnitude and position of the balance weights 
needed in order to minimise the disturbing effects of inertia 
and centrifugal action. The result was somewhat surpris- 
ing, indicating that weights of so much as 200 lbs. were 
needed where none were provided, and that for want of these 
weights pressures exceeding by some tons that due to the dead 
weight of the locomotive were imposed on the rails at each 
revolution at not excessively high speeds. A memorandum was 
thereupon drawn up, and appended to the report of the Board 
