ADVERTISEMENTS.

Inside page, each insertion--75 cents a line. Back page, each

insertion--$1.00 a line.

_Engravings may head advertisements at the same rate per line, by

measurement, as the letter press. Advertisements must be received at

publication office as early as Thursday morning to appear in next

issue._

The publishers of this paper guarantee to advertisers a circulation of

not less than 50,000 copies every weekly issue.

* * * * *

Scientific American, Volume XLIII., No. 25, December 18, 1880 A Weekly Journal of Practical Information, Art, Science, Mechanics, Chemistry, and Manufactures. · 第 75 / 165 题