[86] The proof is too involved to be given here. The writer has set it forth in a chapter on the transcendency of π in a work soon to be published by Professor Young of The University of Chicago.
[87] These may be purchased through the Leipziger Lehrmittelanstalt, Leipzig, Germany, which will send catalogues to intending buyers.
[88] An excellent set of stereoscopic views of the figures of solid geometry, prepared by E. M. Langley of Bedford, England, is published by Underwood & Underwood, New York. Such a set may properly have place in a school library or in a classroom in geometry, to be used when it seems advantageous.
[89] The actual construction of these solids is given by Pappus. See his "Mathematicae Collectiones," p. 48, Bologna, 1660.
[90] The illustration is from Dupin, loc. cit.
[91] For the historical bibliography consult G. Holzmüller, Elemente der Stereometrie, Vol. I, p. 181, Leipzig, 1900.
[92] The illustration is from Dupin, loc. cit.
Transcribers notes
On [page 30] Megapontum has been left as printed, though the author probably meant Metapontum.
On [page 269] 100 B.C. has been left as it was printed, though it is probably a typo for 100 A.D.