Transcriber's Notes:
Obvious punctuation errors have been corrected.
Spelling inconsistencies have been retained.
The picture of a pointing finger, known in typography as an index, a manicule, or a fist, has been rendered in this version as "=>".
On page 83, the clause [ "It has an independent extinguisher for the smaller wick tube"] had "ndependent" in the original.
On page 90, the [ illustration of the transit of Jupiter] by a dark body is reversed, as it was in the original.
On page 91, the ad reading [ "The Turbine Wheel made by Risdon & Co., Mt. Holly, N. J., gave the best results at Centennial tests."] had "tets" in the original.
On page 92, the patent named [ "Gas, scintillator for lighting" ]was numbered "204,28" in the original. The final "5" has been added because sorting the list reveals that the patent numbers form a consecutive series from 204,122 to 204,413, with the only one missing being 204,285.
On page 92, the patent named [ "Shoetip" ]was guessed at; the "t" is unclear in the original.
On page 93, the [ ink blot] partially obscuring the 'B' in "Burnham's" was present in the original.