"Why ?" "Then do it.

Just that.

On this side of the notch you will see--when you are close enough--a few adobe buildings.

I want to pass over those buildings at a height of, say, five hundred feet; or a little lower will be better, if you can make it.

Then circle and come back again.
And try and make the return trip as high as you did coming down, until you are well past those mountains we passed over, just inside the line.
Then come down at camp as inconspicuously as possible.