Page:Percival Lowell - an afterglow.djvu/96

Percival Lowell or freezing with deposition of water as rain, sleet, hoarfrost or snow, which is remelted each day and. largely evaporated in the sunshine.

Such a process of repeated deposition and evaporation would shift the water gradually from the melting polar cap-area to the equator and beyond and amount to a flow of water, at least in its effects.

I thought you would be interested to know this climax of a little persistent sky-gazing. I am writing you while the matter is fresh.

I find that though my left eye is perfectly good I cannot see details as with the right eye. This shows that training is needed and one becomes right-eyed just as he becomes dextrous with the right hand by long practice. This accounts, too, for the fact that quite often persons using the telescope or microscope, but who are not accustomed to such use, fail to detect minor details which to the trained eye are not only visible, but even easily seen.

Very truly yours,

P. S. The south polar cap with its border of blue-green was a very interesting sight in itself. Everything was clear cut, sharply defined. 72