[11] Rotating a large mass of iron rapidly in one direction and then in the other in the neighbourhood of a delicately-suspended magnetic needle, well protected from air currents, ought, I think, to give rise to magnetic phenomena of very great interest in the theory of magnetism. I have hitherto failed to obtain any trace of magnetic action, but I attribute my failure to the comparatively slow speed of rotation which I have employed, and to the want of delicacy of my magnetometer. [12] I had applied for a patent for this system of signalling some time before the above words were spoken, but although it was valid I allowed it to lapse in pure shame that I should have so unblushingly patented the use of the work of Fitzgerald, Hertz, and Lodge. [13] How to see by electricity is perfectly well known, but no rich man seems willing to sacrifice the few thousands of pounds which are necessary for making the apparatus. If I could spare the money and time I would spend them in doing this thing--that is, I think so--but it is just possible that if I could afford to throw away three thousand pounds, I might feel greater pleasure in the growth of a great fortune than in any other natural process. [14] Probably first described by Mr. Brennan. [15] The weight of Mr. Brennan's loaded wagon is 313 lb., including gyrostats and storage cells. His two wheels weigh 13 lb. If made of nickel steel and run at their highest safe speed they would weigh much less. * * * * * Changes made against printed original. Page 91. "all that we should have to take into account": duplicated 'that' in original. Page 150. "applied to apples": 'applied to applies' in original. Advertisements. "Persia ... by the Rev. Professor Sayce": 'Professsor' in original.