| Description | Sir Joseph Norman Lockyer has forwarded his letter to him of 20 March, in which Hellard refers to the six inch maps on which the observing stations of the Rucker and Thorpe Magnetic Survey are marked. Those maps are in possession of the Royal Society, and Harrison will gladly give anyone Hellard desires access to them, but he has no present power to send them out of the building, particularly as a similar application is made by the Hydrographer to the Admiralty to obtain access, possible in connection with the same object as Hellard's. |