Mount Monadnock

Abbott Handerson Thayer
  1849 – 1921, was an American artist, naturalist and teacher.  During the last third of his life, he worked together with his son, Gerald Handerson Thayer, on a major book about protective coloration in nature, titled Concealing Coloration in the Animal Kingdom: An Exposition of the Laws of Disguise Through Color and Pattern; Being a Summary of Abbott H. Thayer’s Disclosures.  In particular, beginning in 1892, he wrote about the function of countershading in nature, by which forms appear less round and less solid through inverted shading, by which he accounted for the white undersides of animals. This finding is still accepted widely, and is sometimes now called Thayer’s Law.
First published by Macmillan in 1909, then reissued in 1918, the book had an effect on the use of military camouflage during World War I.
As he aged, he suffered increasingly from panic attacks (which he termed “fright-fits”), nervous exhaustion, and suicidal thoughts, so much so that he was no longer allowed to go out in his boat alone on Dublin Pond.