_( 31st August, 1868.)_ Rain began here this evening, quite remarkable and exceptional, as it precedes the rains generally off the watershed by two months at least: it was a thunder shower, and it and another on the evening of the second were quite partial.
* * * * * [As we shall see, he takes advantage of his late experience to work out an elaborate treatise on the climate of this region, which is exceedingly important, bearing, as it does, upon the question of the periodical floods on the rivers which drain the enormous cistern-lakes of Central Africa.] * * * * * The notion of a rainy zone, in which the clouds deposit their treasures in perpetual showers, has received no confirmation from my observations.

In 1866-7, the rainfall was 42 inches.

In 1867-8, it amounted to 53 inches: this is nearly the same as falls in the same latitudes on the West Coast.

In both years the rains ceased entirely in May, and with the exception of two partial thunder showers on the middle of the watershed, no rain fell till the middle and end of October, and then, even in November, it was partial, and limited to small patches of country; but scarcely a day passed between October and May without a good deal of thunder.

When the thunder began to roll or rumble, that was taken by the natives as an indication of the near cessation of the rains.