| Description | Harrison clears up a misunderstanding that had arisen regarding the maps used with the Rucker and Thorpe Magnetic Survey and deposited with the Royal Society. He knew they had these maps, and without verifying it personally, he assumed them to be the 6 inch maps referred to it Hellard's letter to Sir Norman Lockyer, but this was disproved when Captain Johnston came to inspect them and found them to be one inch maps. Harrison had feared that the six inch maps had been deposited with them and mislaid, but Sir Arthur Rucker has explained that he and Dr Thorpe used one inch maps and these are the ones in the Society's possession.
Harrison hopes he has not caused the Ordnance Survey Office any inconvenience and the Johnston was still able to obtain the data he required from the maps. |