Bulletin 51, New Jersey Geodetic Control Survey Bench Marks in ...

Mr. Meredith E. Johnson, Chief,Division of Geology and Topography,DepaPtment of Conservation and Development,Trenton, New Jersey.Sir: -There are herewith submitted for your approvaland publication additional level data obtained by theNew Jersey Geodetic Control Survey.The organization of this Survey, its purpose andthe methods used in obtaining these data are describedin detail in Bulletin No. 44 published by your depart-_ent in Ig36.The data now submitted cover parts of Burlington,Camden, Gloucester and Salem Counties.The datum used for all elevations given in thisBulletin is Mean Sea Level.Old bench marks have been tied in with the work ofthe New Jersey Geodetic Control Survey and elevations forthem are given in accordance with the least square adjustmentmade by this Survey. All U. S. Coast and Geodetic Surveyfirst and second order benchmarks in the vicinity of thelevel net herein described have been held fixed and are listedin the Appendix.Bench Marks established years ago by the New JerseyGeological Survey have been checked. It was found thatthroughout the area of this level net there has been settlementas compared with the latest least square adjustmentNEW JERSEY GEOLOGICAL SURVEY