100 YEARS AGO

In the Proceedings of the American Philosophical Society for December 1901 (vol. xl. No. 167), Mr. Percival Lowell refers at some length to the observations that led to the announcement in the Press that Mars had been signaling to the earth on a night in December 1900. It may be mentioned that the original dispatch read as follows:— “Projection observed last night over Icarium Mare, lasting seventy minutes.” (Signed) “Douglas.” In the present paper Mr. Lowell describes in detail some of the individual observations, and points out how the Flagstaff observations of 1894 showed that on general principles the Martian projections were most probably not due to the existence of mountain peaks. A close study of the surface markings led both Messrs. Lowell and Douglas to the result that these several projections were not caused by such permanent suface markings as mountains, but were the effect of clouds floating in the planet's atmosphere... Mr. Lowell, in his concluding remarks, says that the surface marking, Icarium Mare, is undoubtedly a great tract of vegetation, and the observation of December is completely explained if it be assumed that a cloud was formed over this region and rose to a height of thirteen miles, and then, traveling east by north at about twenty-seven miles an hour, passed over the desert of Aeria and there was dissipated.

From Nature 1 May 1902.

50 YEARS AGO

A new field of the application of television was opened up about a year ago when, at the request of the admiralty, Marconi's Wireless Telegraph Co., Ltd., hurriedly assembled a television camera chain in an attempt to find the lost submarine Affray. A great deal of development work has since been carried out in co-operation with Siebe, Gorman and Co., Ltd.; and recently (April 17) a demonstration of the newly designed equipment was given in an experimental tank at the works of this Company. Among the special features of the apparatus shown were the use of the extremely sensitive image-orthicon camera tube, the enclosure of this camera and its associated components in a chamber capable of withstanding the water pressure prevailing at great depths, and the provision of remote-control facilities whereby the camera may be focused and directed by the operator who remains on the ship above.

From Nature 3 May 1952.