TWO FINDS ON MOUNT KENIA 
61 
was largely concerned in the organisation of the expedition 
which, in the year 1899, resulted in Mr. Mackinder’s achieving 
the first ascent to the summit, in company with two Swiss 
guides, Cesar and Joseph. This Hausburg valley may be 
easily reached in four days from the Government station of 
Nyeri. It is of interest as containing some of the clearest 
indications to be seen on the mountain of the much-extended 
glaciation which prevailed upon it in past ages. A succession 
of moraines run across the valley like long curved railway 
embankments at distances ranging up to three or four miles 
below the present limit of the ice. Before reaching this point, 
the writer had almost completed an entire circuit of the moun- 
tain, starting on the south side and passing round by the 
east and north, and arriving, a few days after leaving the 
Hausburg valley, at the starting point again. Throughout this 
journey, nothing but igneous rocks had been met with, but here, 
high up on the northern slopes of the valley at an altitude of 
close upon 18,000 feet, one comes across an exposure of sedi- 
mentary rocks. Below them was an unknown thickness of 
igneous rocks. In turn they were overlain by heavy lava 
flows of several hundred feet in thickness. They appear to be 
composed of a fine ash of a dull buff colour. The exposure 
consisted of a vertical face, of a depth of ten or twelve feet, 1 
underneath an overhanging ledge of rock, projecting almost 
horizontally for about eight or ten feet forward from the 
vertical face alluded to. A striking feature, as one looked up 
at this overhanging shelf from below, was a very regular wavy 
pattern left on its under side as the softer stratified ash below 
had weathered away and fallen down (see Illustration No. 1). 
One could not help coming to the conclusion that these were a 
‘ cast ’ of ripple-marks — the effect of wave action on a shore 
composed of the fine ash in question. One is immediately 
faced with the problem as to what conditions could have existed 
to provide a shore-line subjected to wave action at this altitude. 
They may have been formed when the stream descending 
this quarter of the mountain was a broader and fuller river, 
1 A photograph of this feature has been deposited in the Society’s 
Museum at Nairobi. 
