Homemade Antique Stereoview of White Horse Ledge / Echo Lake, NH

I love this double image formally, with perfectly round mound (White Horse Ledge, we know from a handwritten note on reverse, an 800-foot cliff in the White Mountains of New Hampshire) and its mirror reflection in the lake (aptly named Echo Lake) looking like the earth itself on the horizon. Times two. And then at right is what looks a bit like a person fishing at the edge of land, or like a small lean-to sort of structure, its a bit hard to tell.  To my eye quite a beauty.

6 7/8" x 3 3/8" and in good condition, albumen photos mounted on card, with some scattered stains but no warping. Handwritten attribution on reverse.