Produced by Juliet Sutherland, Josephine Paolucci and the Online Distributed Proofreading Team at www.pgdp.net [Illustration] SCIENTIFIC AMERICAN SUPPLEMENT NO. 508 NEW YORK, SEPTEMBER 26, 1885 Scientific American Supplement. Vol. XX., No. 508. Scientific American established 1845 Scientific American Supplement, $5 a year. Scientific American and Supplement, $7 a year. * * * * * TABLE OF CONTENTS PAGE I. CHEMISTRY AND METALLURGY.--The Cowles Electric Smelting Process. 5 figures. 8113 On the Electrical Furnace and the Reduction of the Oxides of Boron, Silicon, Aluminum, and other Metals by Carbon.--By EUGENE H. COWLES, ALFRED H. COWLES, and CHARLES F. MABERY. 8112 Chemical Action of Light. 8117 Eutexia.--Cryohydrates.--Eutectic salt alloys and metal alloys. 8117 Chinoline. 8118 Method of Rapid Estimation of Urea. 1 figure. 8118 Assay of Earthenware Glaze. 8112 II. ENGINEERING AND MECHANICS.--Deep Shafts and Deep Mining. 8104 Sinking of the Quievrechain Working Shaft.--Numerous figures. 8108 On the Elementary Principles of the Gas Engine.--An interesting paper read before the Gas Institute by Mr. DENNY LANE, of Cork, and discussion following. 8109 M. MEIZEL'S Reciprocating Exhauster. 8112 Automatic Siphon for Irrigation. 1 figure. 8113 III. ELECTRICITY, TELEGRAPHY, ETC.--Optical Telegraphy.-- Cryptography.--Preservation of Telegrams.--The projector in optical telegraphy.--Use of balloons. 4 figures. 8114 A New Style of Submarine Telegraph. 4 figures. 8115 A New Circuit Cutter. 2 figures. 8115 New Micro Telephonic Apparatus. 5 figures. 8116 Messrs. Kapp and Crompton's Measuring Instruments. 5 figures. 8116 IV. GEOLOGY, ETC.--Permeability of Sand Rock.--By F.H. NEWELL. 8103 The Grotto of Gargas, in the Pyrenees.--Paleontological remains found therein. 2 engravings. 8103 Remarkable Wells and Caverns in Yucatan.--By ALICE D. LE PLONGEON. 8105 V. NATURAL HISTORY.--The Cabbage Butterfly and the Peacock Butterfly. 8105 VI. BOTANY AND HORTICULTURE.--The Bhotan Cypress (Cupressus torulosa).--With engraving. 8106