Other stars situated near the one in question will also send beams of light along slightly different directions to the lens, and these will be concentrated, each in its appropriate place, in the focal plane, F H, passed through the focus, F, perpendicular to the line, F G, and we shall find in this plane a picture of all the stars or other objects within the range of the lens.
"A Text-Book of Astronomy"
George C. Comstock
The American Floras are nearly as many as the 15 natural regions already indicated, each having a focal seat or cradle in some range of mountains.
"The American Nations, Vol. I."
C. S. Rafinesque
It is not the wilderness, nor the low lands, nor the level places, but Mount Carmel, Mount Horeb, Mount Zion, the Mount of the Beatitudes and the Mount of Transfiguration that are focal points of righteousness and faith.
"The Jericho Road"
W. Bion Adkins