This {p.013} system constitutes the main chain of communications, as the term is understood in war; by it chiefly, for much of the distance wholly, must come all the ammunition, most of the food, and not improbably at times a good deal of the water drunk during the dry season, which fortunately, from this point of view, is also that of cooler weather.
The difficulty of reinforcing railway carriage by any other system of road transportation is greatly increased by the local horse-sickness, from which three-fourths of the horses exposed to it die.

Reliance for that purpose, therefore, must be upon the ox-wagon, which for this reason, and owing to the open level character of the country, has in the past played a leading part in the South African migrations.
The main and subsidiary railroads thus summarized should, from the point of view of our subject, be considered as one, contributory to the advance of the British army over a substantially even country, which opposes few natural obstacles to such a movement, though here and there "accidents of {p.014} the ground"-- a range of hills, or a dry river-bed, as at Paardeberg--may facilitate opposition by a military force.

The system receives no further support until Johannesburg is reached.

There the railroad from Durban comes in, and, if its carrying capacity were adequate, which is doubtful, would enable the chief base of operations and main line of communications to be shifted to the nearer locality, retaining the Cape road only as secondary.
The advantage to the British of the line of invasion from Cape Town is that it crosses the mountains, which separate the coast district from the inland plateau, at such a distance from the enemy's frontier that it is impossible for the latter to offer serious resistance before the comparatively easy rolling country has been reached.

It was for this reason that the decision of the Orange Free State to join in the war, while it added to the numerical resistance to be encountered by the British, had for them the compensating advantage that it removed the necessity of forcing their way over the difficult mountain ranges which separate Natal from the Transvaal.
With the power of Great Britain to bring into {p.015} the field a great superiority of numbers, it is at least open to argument that the Free State, by ceasing to be neutral, relieved the enemy of a difficulty greater than that which its hostility introduced.