This last lip of the lake has surely overflowed, and is overflowing still, though very slowly.

Its furrows all curve downward; and it is, in fact, as one of our party said, 'a black glacier.' The pitch, expanding under the burning sun of day, must needs expand most towards the line of least resistance, that is, downhill; and when it contracts again under the coolness of night, it contracts, surely from the same cause, more downhill than it does uphill; and so each particle never returns to the spot whence it started, but rather drags the particles above it downward toward itself.

At least, so it seemed to us.

Thus may be explained the common mistake which is noticed by Messrs.

Wall and Sawkins {148b} in their admirable description of the lake.
'All previous descriptions refer the bituminous matter scattered over the La Brea district, and especially that between the village and the lake, to streams which have issued at some former epoch from the lake, and extended into the sea.