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The Flight of the Invisible Airplane, 1915

Innovation and discovery as chronicled in Scientific American

December 1965

The life of the “Untouchables” of India
“Without violence or much notice from the outside world India is undergoing a profound social revolution. Religious sanctions as well as economic, social and legal ones have traditionally enforced the inferior position of the lower castes. Today the nation's new constitution and its government are firmly committed to the overthrow of those traditions. For understandable reasons the people of India themselves have always avoided the term “untouchables.” Most people in India now call the former untouchables by the name Mahatma Gandhi gave them: Harijans, or ‘children of God.’ Under the law the Harijans are now free to adopt whatever style of life they choose; all the traditional taboos are legally abolished. The law says they may dress as they please, drink from any village well, enter any Hindu temple.”

Cigarettes and atherosclerosis
“A direct association has been established between cigarette smoking and coronary atherosclerosis, the condition in which fatty deposits build up in the arteries of the heart and reduce their interior diameter. Earlier studies had shown that the risk of coronary disease and of death from heart attacks is higher among cigarette smokers than among nonsmokers. These studies told nothing about a smoker's arteries, however; they could have meant merely that smoking imposes added burdens on the heart. Now researchers have reported that an advanced degree of coronary atherosclerosis is more common in cigarette smokers than in nonsmokers, and that it increases with the amount of smoking.”


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December 1915

Dreams of invisibility
“Military authorities await with great interest the development of the new French invisible aeroplane, which bids fair to revolutionize aerial warfare. The body and framework are constructed, as in ordinary machines, of aluminum braced with wire. Over the framework, instead of canvas, is stretched a transparent material which looks like a cross between mica and celluloid [see illustration]. It is called ‘cellon,’ and is a chemical combination of cellulose and acetic acid. Of almost the same transparency as glass, it does not crack or splinter and has the toughness and pliability of rubber.”

Radium for crop health
“A radium fertilizer is sold by a company recommending one pound to 50 square feet of soil. R. R. Ramsey estimates that this adds to the soil only one tenth the amount already there—an evident waste of good money. To double the amount of radium emanation available for crops, the farmer must sow seventy-five milligrams of radium to an acre at the trifling price of $7,500. It is evident that even the most modern farmer will remain satisfied with such stock of radium as is now locked up in his farm.”

December 1865

Doubt on geothermal
“At the last meeting of the Literary and Philosophical Society of Manchester, Mr. George Greaves read a paper embodying the suggestion that the ‘internal heat of the earth’ should itself be employed in place of fuel. He considers that the heat of the fiery ocean which he believes lies under our feet might supply us with all the mechanical power we want, and that one method of causing it to do this ‘might be by the direct production of steam power by bringing a supply of water from the surface in contact with sufficiently heated strata, by means of artesian borings or otherwise.’ He has yet to explain, however, how, supposing his ‘sufficiently heated strata’ to really exist, we could make ‘artesian borings’ deep enough to reach them.”

Science and weather
“The daily record of meteorological observations telegraphed to the Imperial Observatory at Paris, and published in a lithographed sheet, continues to increase in interest and importance under the active and enlightened superintendence of M. Le Verrier, director of the observatory. The outline chart of Europe, with the curves of equal barometric pressure and direction of the wind at the different situations of the day of publication, and also a table of the estimated weather for the following day, continue to be inserted in every number.”

Scientific American Magazine Vol 313 Issue 6This article was originally published with the title “50, 100 & 150 Years Ago” in Scientific American Magazine Vol. 313 No. 6 (), p. 83
doi:10.1038/scientificamerican1215-83