4 The American Geologist. July, i898 
bringing materials, and hence a point grows outward. The 
shore currents are operating in the same direction and hence 
are cooperating; but they are doing much less than the waves, 
and are moving only clay and sand, which of course, are made 
to enter into the structure of the spit. 
One may well ask why the spit began, and when it will end. 
I am not certain that I fully and clearly understand this point, 
though I see plainly that it is through no chance or accidental 
conditions that the spit develops. It has an explanation in 
the law, everywhere illustrated on coast lines, that waves sup- 
plied with material will discover the easiest means of dis- 
posing of it. In the case of Crowbar point the waves were, 
in the first place, driving materials both ways, the south winds 
pushing the pebbles toward the north and the north winds 
driving' them in the reverse direction. There was a bend in 
the coast due to the projection of the old land; to this the 
waves from the south brought materials, but there they lost 
some of their power, and hehce could not continue to carry 
all their load beyond the point, so some was dropped on the 
very point. The same was true of the waves from the north. 
They were able not merely to drive along the materials which 
they had wrested from the rocks, but also to turn back some 
of the debris which the south waves had driven beyond the 
point. But when these waves passed the point tlicy lost their 
force likewise, and so both north- and south-moving waves 
made this a dumping ground. As they built the spit out into 
the water, the interference of the point with the movement 
of materials to the north or south became greater and greater, 
until, at present, the spit forms an almost perfect barrier for 
the larger fragments. Had the south waves been greatly less 
powerful than those from the north, there would have been 
built a bar extending nearly parallel to the coast; but with 
nearly perfectly balanced waves from the two directions, the 
spit must grow directly outward. 
The other question is whether the spit will continue to 
grow^ outward indefinitely. Granting the continuation of the 
present conditions, the spit must finally destroy the cause for 
its further extension, and, I believe, as the next stage, become 
a hook, bending toward the south. 
As it grows out into the lake, enough material is still driven 
