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Show Mil GEOGRAPHIC POSITIONS POSI-TIONS INJ1 DETERMINED Tho making of n topographic map of tlia Stato of Ohio was commenced by tlio United States Geological Survey Sur-vey In 1897 and slnco 1900 tho work has been carried on In cooperation with tho Stato. About 95 por cent of tho area has now been completely survoyod. In ordor that tho map may bo of convenient form for handling, it Is Issued In sheets about 10x20 ltuhes In size, each sheet covering an urea ot nbput 200 squaro nillos. Tho boundaries of tho areas shown on the sheets aro parallols ot latitude aud meridians ot longitude. Nearly 5,400 primary geographic positions havo been determined for tho accurate control of tho Ohio maps and tho results of this work havo Just been published by tho United States Ocologlcal Survey In Bulletin uj2, which Includes also an Index map showing tho location of tho trl anguatlon and travorso stations for each sheet and an engraved plato Illustrating Il-lustrating tho various kinds of metal markers used. It Is tho plan of tho Geological Survey to Issue such bulletins bul-letins for each Stato. Ohio Is tho first Stato for which tho comploto control data woro published In a single sin-gle Yolumo, This bullotln will no doubt bo of considerable valuo to engineers and surveyors, as it gives acturato data on which their work may bo based. It may bo had freo of cost on request sent to tho Director ot tho United States Geological Survoy, Washing' ton, D. O. |
