Towards evening we reached the first spur of the heights in the Free State, running due north and south. The vegetation was already becoming more luxuriant. A large number of shrubs that from the diamond-fields had looked mere specks turned out to be camel-thorn acacias, their broad-spreading crowns and great flat seed-pods declaring them akin to the mimosas. Since that date most of them have fallen under the axe, and they have been reduced to ashes as fuel at the diggings. Their trunks are often two feet thick, covered with a rough dark-grey bark, full of knots, and yielding a sound hard wood. Two things particularly arrested our attention; first, the great thorns growing in pairs three inches long, with their points far asunder, and at the base as thick as a man’s finger; and, secondly, the collections of strange birds’ nests hanging down from the branches. These nests belonged to a colony of the sociable weaver-birds (Philetærus socius), and their construction was very singular. When the birds have found a suitable branch, the whole flock sets to work with the industry of bees to make a common erection that may shelter them all. Each pair of birds really builds its own nest of dry grass and covers it in; but so closely are the nests fitted together, that when finished the entire fabric has the appearance of one huge nest covered in by a single conical roof, the whole being often not less than three feet high and from two to five feet in diameter. The boughs which project beyond the structure are not unfrequently known to break under
