I was playing around with Internet Archive last night and found this interesting item: It's a scanned copy of "New Measures of the Great Pyramid" by Charles Piazzi Smyth published in 1884. He's the one who wrote "Our Inheritance in the Great Pyramid" which C.T. Russell relied on for his pyramid theories. (In fact, C.T. Russell even advertised the "Our Inheritance" book in the back of the first edition of "Thy Kingdom Come," Vol 3 of Millennial Dawn.
This other book by Smyth (which I'd never heard of before) is online at:
http://www.archive.org/details/newmeasuresofgre00smytiala
What's fascinating is it apparently was once in Morton Edgar's personal library and contains many handwritten notes by him in the margins. Morton Edgar published "Great Pyramid Passages" which he wrote with his brother, John Edgar, and which Russell also advertised and sold through the Society. The Edgars are mentioned in various Watchtower publications up until about 1924. John Edgar had been named by C.T. Russell in his will as a possible member of the Editorial Committee for the Watchtower magazine but John died before Russell did. Morton remained with the Watchtower Organization up until 1928 when Rutherford denounced pyramidology as a work of Satan.
Anyway, this is a fascinating item for history buffs.