Anyone sending a sketch and description csay qnlckly ascertain our opinion free whether an invention is probably patentable. Communications strictly condeutial. HANDBOOK on Patents sent free. Oldest airency for secariner patenta. Patents taken tbroufrh Munn & Co. receive special notict without charge, in the Scientific Hntericam A handsomely illustrated weekly. Largest dr-onlation of any scientific Journal. Terms, $3 fi year : four months, f L Sold by all newsdealers. Brancb Office. OiW BU Washington, D. C.
This article was originally published with the title "Patents" in Scientific American 97, 19, 351 (November 1907)