Some proprietors of mail coaches are in the habit of administering doses of arsenic to their horses and mules, which are said to operate in lessening the death rate and to favour the salting process.

As safeguards for horses and mules, the following rules have been found to minimise losses in dangerous tracts where the low clinging miasmatic vapours are so deadly during the night and earlier parts of the morning.  (During rainfall there is hardly any danger, nor is there after a night’s rain for the day following):—­

Do not traverse low suspicious tracts during the hours between 9 p.m. and, say, two hours after sunrise, lest poisonous vapours be encountered and inhaled by man or horse.

Choose the most elevated spots for camping out at night.  No grazing to be allowed from 10 p.m. to about 10 or 11 a.m., unless it is raining.  Dewy grass is fatally poisoned; the heavy moist air close to the surface is also suspected.  Grazing is only safe after the soil and grass are dried of all dewy moisture.

Avoid all water of at all a stagnant nature; rather let the animals remain thirsty.

If the animals have been fed with dry fodder during the night, let the first morning stage be moderate and not exhausting.  With empty stomachs the task might be somewhat increased, but even then it should be less than any other succeeding stage.  When the first symptoms of sickness are noticed they may pass over if the animal is at once freed from work and allowed to rest, or is at most led when marching.  Among the most dangerous places for horse sickness and for fever to human beings are the luxurious dongas, ravines, and valleys which abound along the long stretches of mountains and broken country immediately below the high plateaux.

The passes leading up to the high veldt are few in number, and so precipitous as to be almost impracticable for vehicles.  Of late years those roads have been allowed to fall into disrepair, in order, it may be supposed, to check wagon traffic and to promote that by railway; apart from the railway, communication with Delagoa Bay would now be impossible.  What with the fever climate in summer, and the formidable mountain barriers, the Transvaal high veldt is well protected from aggression from the direction of Delagoa Bay.  A few thousand men distributed at the few mountain passes, blocking the tunnel at one of these (at Waterval Boven), and breaking up some few bridges, would effectually arrest the progress of any invading force.

CLIMATE AND TOPOGRAPHY