In the earlier period of railway history of this country, the great trunk-lines were so far separated as to be independent of each other, and, as it were, isolated in their respective districts, and no diversity of gauge was then likely to interfere with the personal convenience, or the commercial objects of the community; but now that railways are spreading in all directions, and becoming interlaced with each other in numerous places, that isolation is removed, that independence has ceased, and the time has arrived when, if steps cannot be taken to remove the existing evil of the diversity of gauge, a wider spread of this evil should be prevented. The commissioners having arrived at the decision that equalization is desirable, they proceed to consider what gauge would be the most eligible to adopt, under the following four heads:-

1. Comparative Safety of the different Gauges. - Experience has shown that railway accidents arise from collisions, obstructions on the road, points wrongly placed, slips in cuttings, subsidence of embankments, a defective state of the permanent way, loss of gauge, broken or loose chairs, fractures of wheels or axles, etc, and lastly from engines running off the lines from some other cause. Of these several causes of accidents, all except the last are obviously independent of the gauge; and with reference to the last, it does not appear that either of the gauges possesses more security than the other against such accidents. Only six accidents of the kind occurred between October 1840, and May 1845; whereas there have been no less than seven during the last seven months; and these last are all attributable to excessive speed, the majority having happened to express trains. Of these 13 acidents, 10 have occurred on the narrow gauge, and only three on the broad; but as there are 1901 miles on the narrow gauge, and only 274 on the broad, therefore the comparison per mile is in favour of the narrow.

Nevertheless, as the speed on the Great Western much exceeded that on the narrow lines, some allowance is due on that score.

The primary causes of engines getting off the rails appear to be overdriving, a defective road, a bad joint, or a badly balanced engine. If, in consequence of heavy rains or other unfavourable circumstances, any part of the road becomes unsound, the engine sinks on one side as it passes along such part of the rail, suddenly rises again, and is thus thrown into a rocking and lateral oscillatory motion, with more or less of violence according to the rate of speed; and a very similar effect is produced in passing at high speed, from one curve to another of different curvature. A succession of strains is thus thrown upon the rails, and if, before the rocking subsides, the wheel meets with a defective chair or rail, which yields to the impulse, the engine and train are thrown off as a necessary consequence; but such casualties, as far as we can see, are equally liable to happen to both gauges.

Several differences in the construction of the broad and narrow gauge engines, with regard to their proportions and adjustments of the weight, have been supposed to operate as a cause of their running off the line. These points have been investigated by the commissioners; but they sum up their remarks on the score of safety by stating, - "Upon the whole, therefore, after the most careful consideration of this part of the subject, we feel bound to report, that as regards the safety of the passenger, no preference is due with well-proportioned engines to either gauge, except perhaps at very high velocities, where we think a preference would be due to the broad gauge." The next question entertained was,

2. The relative accommodation and convenience for Passengers and Goods on each Gauge. - The first class carriages of the broad gauge are intended to carr eight passengers in each compartment, and the compartments are sometimes divided by a partition and inside door. On the narrow gauge lines, the first class carriages are usually constructed to carry only six passengers in each compartment; and the same width is allowed for each passenger in both gauges. Until recently the broad gauge carriages were altogether more commodious than those on the narrow, but now the first class carriages on the narrow gauges possess equal commodiousness; they are both highly so.

In the second class carriages on the broad gauge, six persons sit side by side, each carriage being capable of holding 72 passengers. On the narrow gauge, generally, only four persons sit side by side, the total number in each carriage being: 32. These last are the most comfortable of the two.

With respect to the ease of the carriage, or the smoothness of motion, the evidence taken is conflicting, but the experience of the commissioners led them to consider, that at the higher velocities, the motion is usually smoother on the broad gauge.

With respect to the conveyance of merchandise, such as manufactured goods and their raw materials; mineral products, such as coal, lime, iron and other ores; agricultural produce, such as corn, hops, wool, cattle and timber; the evidence of intelligent persons engaged in the carrying business has been taken, who expressed a strong opinion that the smaller is far the most convenient and economical. Another advantage of the smaller waggons is its economy in lessening the dead weight, where full loads cannot be obtained at the stations. Here the dead weight would be greatly increased on the broad gauge, unless the greater commercial evil were sustained of waiting until full loads were accumulated. For the foregoing reasons, the commissioners decide that the narrow gauge is the most convenient for the merchandise of the country.