MAGAZINE OF SCIENCE AND ART. 
81 
strength and weight must, in the first instance, be laid 
down. 
The more \ve study economy and safety in laying out 
lines of railway in Australia,’ the more will their use 
and their benefits be promoted. With respect to the 
“ guage” of railways, it is not necessary to shew the 
advantage of one uniform breadth of wav between _ the 
rails ; but what that breadth or guage should ho, is a 
question of some importance. 
It seems probable that in the construction of the first 
British railways, the guage of 4 ft. 8 -V in. was adopted 
without any consideration whether that guage was the 
most advantageous in the new method of locomotion, 
but simply because that was the ordinary breadth be¬ 
tween the* wheels of carriages on common roads. 
Mr. Brunei was the first engineer who deviated from 
the ordinary mode of constructing railways, by increas¬ 
ing the guage to 7 feet between the rails on the Great 
Western Railway ; and the prominent reasons assigned 
for this deviation were, first, increased steadiness to the 
carriages and engines ; second, increased power and the 
attainment of a higher rate of speed ; and, thirdly, a 
diminution of axle-friction by the use of wheels of a 
larger diameter, with outside bearings. 
The broad guage which has been so much reviled by 
the admirers of the narrow guage. Is most unquestion¬ 
ably the best to attain the benefits above mentioned, at 
a certain increase of expenditure in the first - instance. 
It is in fact siraplv a question of cost, for it is an un¬ 
doubted fact that just as good a road can be made with 
a 7 feet guage as with one of 4 ft. 8 i in. 
In determining the question of guage in a country 
like Australia, as yet almost untouched by these works, 
it should be considered quite independently of the 
guage that has been adopted in other countries : for it 
can be demonstrated that 4 ft. in. is not exactly the 
proper width for all railways, and that to adopt any 
other width is not a departure from a rule which ex¬ 
perience has found to be correct. 
A guage of six feet between the rails would have the 
effect of affording increased steadiness to the carriages, 
by lowering their centre of gravity. The wheels might 
also be made with outside bearings, and their diameter 
might be increased to 4 or 5 feet, which would reduce 
the amount of friction in the proportion of 10 to 7. A 
greater distance, as 7 feet, would allow of wheels of G 
or 7 feet in diameter, which would reduce the friction 
by nearly one-half; but it is doubtful whether the 
diameter should be so great. 
It is clearly advantageous to reduce the friction on 
the axle, and‘the resistance on the rails, as much as 
possible, which, all other tilings being the same, will he 
inversely proportional to the diameter of the wheels, 
and there can he no doubt that, in a new country, pro¬ 
vision should be made for taking advantage 0 f these 
improvements, and of regulating our principles of con¬ 
struction so that any further improvements may be 
taken advantage of, and to increase the guage of our 
future lines of railway to not less than 6 feet, between 
tbe rails, the advantages of which, it is presumed, will 
be cheaply purchased by a small addition to the first 
outlay. 
Horse-Power. —Tt is too common for the advocates 
of high speed and higli cost railways, to overlook en¬ 
tirely the beautiful conformation of the horse. So ad¬ 
mirably is this noble animal adapted by physical 
structure for the exertion of tractive power in the trans¬ 
port of weights, that he is enabled, without any assistant 
power, to overcome, b> a momentary effort, almost any 
inclination that can occur on a railway; and, therefore, 
steeper inclinations than 1 in 250 are comparatively 
unimportant where horse-power is used. The type of 
the American railroad is the old horse tramway, and 
so long as they were worked by horses, the American 
lines were highly successful ; but the traffic has out¬ 
grown horse-power, and steam has been applied on a 
system of road construction not adapted to it. A net¬ 
work of 26,000 miles of railway now covers the United 
States and the cost of construction per mile has seldom 
or ever exceeded <£ 10,000 or <£ 12,000 per mile, as com¬ 
pared with nearly £4t),000 on British railways. 
Mr. Judgold in his valuable and undervalued publi¬ 
cation on railways, has directed his attention to the 
subject of horse-power, and the fo Wo wing table of his 
affords information of great practical utility in esti¬ 
mating the average labour of horses, at different veloci¬ 
ties, in tons drawn one mile, on canals, railways, and 
turnpike roads. 
I 
Velocity in miles, per 
hour. 
Duration of the day’s 
work at the preceding 
velocity. _ 
. I 
CQ 
J3 
•S 
£ 
O 
o 
ci 
s 
<+-. 
o 
p 
o 
Useful effect of 1 horse work¬ 
ing 1 day, in tons drawn 1 
mile. 
On a canal. 
On a level 
Railway. 
o 
8 ^ 
fcl ; i=h 
*4 2 
a s 
OH 
[Miles. 
Hours. 
lbs. 
Tons. 
Tons. 
Tons. 
24 
114 
S34 
520 
115 
14 
3 
8 
243 
92 
12 
3i 
5.9 
153 
82 
10 
4 
4.5 
102 
72 
9 
5 
2.9 
52 
57 
7.2 
6 
2 
30 
48 
6 
1.5 
19 
41 
5.1 
8 
1.1 
12.8 
36 
4.5 
9 
0.9 
9 
32 
4 
10 
0.75 
’* 
6.6 
28.8 
3.6 
It must, however, be noticed that although these de¬ 
ductions of Mr. Judgold’s are sufficiently accurate up 
to rates of 4 or 5 miles an hour, yet, when boats are 
moved on canals by horses at rates of 9 to 12 miles an 
hour, the circumstances of the resistances undergo an 
essential change. The resistance in fact diminishes as 
the speed in cr eases ^ and it becomes so small that pas¬ 
sage boats on canals now travel at the high velocity of 
10 or 12 miles an hour without injury to the horses, 
which in fact perform their work better at the increased 
speed. This discovery is an important one, as boats 
might travel at the rate of 15 or oven 20 miles an hour 
in this manner; and it is hence probable that railroads 
and canals will admit of a competition snoh as the sup¬ 
porters of the former never anticipated. 
If wo take Professor Leslie’s formula for the power 
of the draught horse, it is as follows, viz., (15—0)2 for 
the traction of a strong liorse; and ( 12 — 0)2 for the 
traction of an ordinary horse. 
According to the first formula, a home travelling at 
the rate of 3 miles an hour exerts a force of 144 lbs; 
and according to the second, 81 lbs. only. Tbe mean 
of these two on 112 lbs. is probably nearer to the abso¬ 
lute force exerted by a home of ordinary strength. 
When horse-power is employed on a railway, the 
calculation is a simple one ; for’assuming the most fa¬ 
vourable pace of a draught horse to be 2 £ miles an hour, 
a horse of ordinary strength will draw, at this rate, 
with a force of 150 lbs., a distance of 20 miles per day. 
Such a horse would, therefore, draw on a level railway, 
the friction being 9 lbs. per ton, a gross load of 16§ 
tons; or two such horses would draw a gross load of 
33£ tons. Considerably heavier loads than this have 
been drawn on a railway by a single horse, for short 
distances, but the above may be considered a fair 
average. 
Upon a level macadamized road a fair load for a 
horse is 1 ton net, so that on a level railway, his work 
being taken at 15 tous net, w ould be equal to 15 times 
as much as upon a good macadamized road. 
The result is, of course, affected by the speed, and by 
the nature of the gradients on the line; for if we in- 
I crease his speed to 5 miles an hour, his tractive power 
