00000nam 2200000za 4500 9.842129 CaOODSP 20221107152245 cr ||||||||||| 170821q1988 onc ||||o f|0| 0 eng d CaOODSP eng n-cn--- M183-4/88-2E-PDF Newitt, L.R. Pier differences at Ottawa Magnetic Observatory [electronic resource] / L.R. Newitt. [Ottawa] : Geophysics Division, Geological Survey of Canada, [1988] 9, [1] p. Internal report ; no. 88-2 Digitized edition from print [produced by Natural Resources Canada]. "In late 1987, new marble piers were installed in Ottawa absolute Building No 4 to replace piers B, C, D, and E which were made of concrete. After the installation of the piers, the GSM-18 proton magnetometer was used to determine differences in total intensity between piers. ..."--p. 2. gccst Geophysics Canada. Energy, Mines and Resources Canada. Geological Survey of Canada. Geophysics Division. Internal report (Geological Survey of Canada. Geophysics Division) no. 88-2 (CaOODSP)9.842124 PDF 1.33 MB https://publications.gc.ca/collections/collection_2017/rncan-nrcan/M183-4-88-2-eng.pdf