seek for some other way of accounting for the sticks—­which utterly puzzled us, and which Mr. Manross well describes as ’numerous pieces of wood which, being involved in the pitch, are constantly coming to the surface.  They are often several feet in length, and five or six inches in diameter.  On caching the surface they generally assume an upright position, one end being detained in the pitch, while the other is elevated by the lifting of the middle.  They may be seen at frequent intervals over the lake, standing up to the height of two or even three feet.  They look like stumps of trees protruding through the pitch; but their parvenu character is curiously betrayed by a ragged cap of pitch which invariably covers the top, and hangs down like hounds’ ears on either side.’

Whence do they come?  Have they been blown on to the lake, or left behind by man? or are they fossil trees, integral parts of the vegetable stratum below which is continually rolling upward? or are they of both kinds?  I do not know.  Only this is certain, as Messrs. Wall and Sawkins have pointed out, that not only ’the purer varieties of asphalt, such as approach or are identical with asphalt glance, have been observed’ (though not, I think, in the lake itself) ’in isolated masses, where there was little doubt of their proceeding from ligneous substances of larger dimensions, such as roots and pieces of trunks and branches;’ but moreover, that ’it is also necessary to admit a species of conversion by contact; since pieces of wood included accidentally in the asphalt, for example, by dropping from overhanging vegetation, are often found partially transformed into the material.’  This is a statement which we verified again and again; as we did the one which follows, namely, that the hollow bubbles which abound on the surface of the pitch ‘generally contain traces of the lighter portions of vegetation,’ and ’are manifestly derived from leaves, etc., which are blown about the lake by the wind, and are covered with asphalt, and as they become asphalt themselves, give off gases, which form bubbles round them.’

But how is it that those logs stand up out of the asphalt, with asphalt caps and hounds’ ears (as Mr. Manross well phrases it) on the tops of them?

We pushed on across the lake, over the planks which the Negroes laid down from island to island.  Some, meanwhile, preferred a steeple-chase with water-jumps, after the fashion of the midshipmen on a certain second visit to the lake.  How the Negroes grinned delight and surprise at the vagaries of English lads—­a species of animal altogether new to them.  And how they grinned still more when certain staid and portly dignitaries caught the infection, and proved, by more than one good leap, that they too had been English schoolboys—­alas! long, long ago.