April 1961

Tiling “The Dutch artist Maurits C. Escher, now living in Baarn [near Amsterdam], has applied many of the 17 symmetry groups to mosaics in which animal shapes are used for the fundamental regions. One of Escher's amazing mosaics is reproduced on the cover of this issue of Scientific American. Escher is a painter who enjoys playing with mathematical structure. There is a respectable school of aesthetics that views all art as a form of play, and an equally respectable school of mathematics that looks upon all mathematical systems as meaningless games played with symbols according to agreed-upon rules. —Martin Gardner in Mathematical Games”

Economics of Disarmament “The Federal Government of the U.S. has been spending somewhat more than $40 billion per year on the maintenance of the military establishment and the procurement of arms. These outlays have absorbed about 10 per cent of the gross national product, and they have exceeded by several billion dollars the combined net annual investment in manufacturing, service industries, transportation and agriculture. The negotiation of disarmament would eventually raise the possibility of a substantial cut in the military budget. Economists, market analysts and the makers of fiscal policy in Government and business have therefore begun to consider how the economy might otherwise employ the labor, the plant and the physical resources that now serve—directly and indirectly—the demands of the military establishment. —Wassily W. Leontief and Marvin Hoffenberg” Leontief was awarded the economics prize from the Nobel Foundation in 1973.

April 1911

Race to the South Pole “Word has been received from Capt. Scott that Amundsen, like himself, is trying to reach the South Pole. Scott's ship, the ‘Terra Nova,’ has returned to New Zealand after landing sledge parties on the ice, and has brought messages from Capt. Scott himself. It seems that Lieut. Pennell, of the expedition, found the ‘Fram,’ Amundsen's ship, in Iceland Bay, and a Norwegian party fully equipped for a journey to the South Pole. On board the ‘Fram’ were eight men and sixteen Greenland dogs. Nothing had been heard of Amundsen's expeditions until news was received from Scott.”

Greenwich Time “On February 10th, 1911, the French Senate passed a bill which makes Greenwich time legal in France. When the law goes into effect, French time will become nine minutes and twenty-one seconds slower than it is now. In order to avoid the expense of altering charts and sailing instructions, the law will not apply to French naval or merchant marine vessels, and it is not likely that any change will be made to the almanacs. French railways are now run by a standard five minutes slower than Paris time, and the clocks inside stations are regulated by this standard, while the clocks on the outside of the station give the correct Paris time. This confusing system will be abolished, and both exterior and interior clocks will be regulated by Greenwich time, by which the trains will be run.”

April 1861

Caesium “The first result of the new method of analysis by the lines of the spectrum was to inform us what substances exist in the sun; the next result is the discovery of two new metals on the earth. One of these has been named caesium, from the color of the peculiar lines in the spectrum of its light; the other is not yet named [later called rubidium]. Caesium resembles potassium in its properties, and exists only in exceedingly small quantities.”

Watchmakers “Frederika Bremer gives the following picture of watchmaking in Geneva: ‘The manufacture of pocket-watches is carried to a great extent in Geneva. An immense number are required for the Chinese market. A well-equipped Chinaman, I have been told, carries a watch on each side of his breast, that he may be able to regulate the one by the other. Wealthy Chinese cover the walls of their rooms with watches. These watches are of a more ornamental character, and have more filigree work upon them than those made for Europeans. Long live the Chinese! At one of the greatest and best conducted manufactories of Geneva, nothing but watch faces are prepared, and elderly, well-dressed and well-looking women sat by twenties and thirties in clean, well-warmed rooms, working upon watch faces.’”

The full article by Bremer, a Swedish feminist writer, is available at www.ScientificAmerican.com/apr2011/bremer