* On examining this subject when I returned to Linyanti, I found that, according to Dr. Arnott, a declivity of three inches per mile gives a velocity in a smooth, straight channel of three miles an hour.  The general velocity of the Zambesi is three miles and three quarters per hour, though in the rocky parts it is sometimes as much as four and a half.  If, however, we make allowances for roughness of bottom, bendings of channel, and sudden descents at cataracts, and say the declivity is even seven inches per mile, those 800 miles between the east coast and the great falls would require less than 500 feet to give the observed velocity, and the additional distance to this point would require but 150 feet of altitude more.  If my observation of this altitude may be depended on, we have a steeper declivity for the Zambesi than for some other great rivers.  The Ganges, for instance, is said to be at 1800 miles from its mouth only 800 feet above the level of the sea, and water requires a month to come that distance.  But there are so many modifying circumstances, it is difficult to draw any reliable conclusion from the currents.  The Chobe is sometimes heard of as flooded, about 40 miles above Linyanti, a fortnight before the inundation reaches that point, but it is very tortuous.  The great river Magdalena falls only 500 feet in a thousand miles; other rivers much more.

The forests became more dense as we went north.  We traveled much more in the deep gloom of the forest than in open sunlight.  No passage existed on either side of the narrow path made by the axe.  Large climbing plants entwined themselves around the trunks and branches of gigantic trees like boa constrictors, and they often do constrict the trees by which they rise, and, killing them, stand erect themselves.  The bark of a fine tree found in abundance here, and called “motuia”, is used by the Barotse for making fish-lines and nets, and the “molompi”, so well adapted for paddles by its lightness and flexibility, was abundant.  There were other trees quite new to my companions; many of them ran up to a height of fifty feet of one thickness, and without branches.

In these forests we first encountered the artificial beehives so commonly met with all the way from this to Angola.  They consist of about five feet of the bark of a tree fifteen or eighteen inches in diameter.  Two incisions are made right round the tree at points five feet apart, then one longitudinal slit from one of these to the other; the workman next lifts up the bark on each side of this slit, and detaches it from the trunk, taking care not to break it, until the whole comes from the tree.  The elasticity of the bark makes it assume the form it had before; the slit is sewed or pegged up with wooden pins, and ends made of coiled grass-rope are inserted, one of which has a hole for the ingress of the bees in the centre, and the hive is complete.  These hives are placed in a horizontal position on high trees in different