Mr. Horace Waller was living for some five months on Mount Morambala, a position from which the whole process of the slave-trade, and depopulation of the country around could be well noted. The mountain overlooks the Shire, the beautiful meanderings of which are distinctly seen, on clear days, for thirty miles. This river was for some time supposed to be closed against Mariano, who, as a mere matter of form, was declared a rebel against the Portuguese flag. When, however, it became no longer possible to keep up the sham, the river was thrown open to him; and Mr. Waller has seen in a single day from fifteen to twenty canoes of different sizes going down, laden with slaves, to the Portuguese settlements from the so-called rebel camp. These cargoes were composed entirely of women and children. For three months this traffic was incessant, and at last, so completely was the mask thrown off, that one of the officials came to pay a visit to Bishop Tozer on another part of the same mountain, and, combining business with pleasure, collected payment for some canoe work done for the Missionary party, and with this purchased slaves from the rebels, who had only to be hailed from the bank of the river. When he had concluded the bargain he trotted the slaves out for inspection in Mr. Waller's presence. This official, Senhor Mesquita, was the only officer who could be forced to live at the Kongone. From certain circumstances in his life, he had fallen under the power of the local Government; all the other Custom-house officers refused to go to Kongone, so here poor Mesquita must live on a miserable pittance--must live, and perhaps slave, sorely against his will. His name is not brought forward with a view of throwing any odium on his character. The disinterested kindness which he showed to Dr. Meller, and others, forbids that he should be mentioned by us with anything like unkindness.