Page:Popular Science Monthly Volume 15.djvu/438

 by a cone of paper, was found to give the best effects. Messrs. Preeee and Stroh also exhibited a machine for tracing curves of the composite character which represent the sounds of speech, especially the vowel sounds. By this machine they are able to build up curves by putting together their constituent parts, and thus to study the various theories with regard to vowel-sounds which have been put forward. Several instruments were shown by which the vowel sounds were reproduced with more or less exactitude by vibrating a disk in accordance with the curves formed by the curve machine. One of them makes a simple and good siren, reliable for measurements, and gives promise of introducing a new musical machine which will give sweet sounds by the mechanical vibration of a disk. Though the knowledge of vowel-sounds is far from complete, Helmholtz's theory has been fully confirmed by the work the authors have done. The sounds can not, however, be, they say, exactly reproduced by mechanical means at present. Some interesting experiments were made on the loudness of sound, tending to show, it was urged, that sufficient importance has not been attached to the quantity of air thrown into vibration. Disks of different diameter, though vibrated with the same amplitude and pitch, increase in loudness very largely with the increasing dimensions of the disk.

A Large Terrestrial Globe.—A New York artificer, Grube, has constructed what purports to be the largest globe of the earth now in existence, showing all the prominent features of its surface. Its diameter is four feet and about one inch, the scale being one to 10,000,000. The range of even the Himalayas would not be visible upon this globe if the same scale were adopted for the elevations as for the map, and accordingly the relief is made upon a scale which exaggerates heights twenty times. The oceans, seas, and rivers are colored blue; the continents are yellow; the glaciers, icebergs and floating cakes of ice, white. Plains and mountain ranges are clearly shown, and every part of the world is exhibited in its true character. Red, black, and white lines cross the globe to indicate the isothermal belts, the variations of the magnetic needle, the date line where ships correct their logs by skipping from Saturday to Monday, and vice versa, and other facts of like character. The map has been corrected in the light of the latest discoveries. The northern coast of Siberia has been much altered in the atlases by the Nordenskjöld Expedition, the ships sailing in deep water over places marked as 500 miles inland, and being compelled to go hundreds of miles around promontories, etc., which are occupied on the maps by bodies of water. The globe is made of wood; the relief is formed by wax. Mr. Grube has been two years in perfecting his globe.

Is the "Uniformity System" an American Idea?—Among the many mechanical geniuses who by their inventions have helped to develop the manufacturing industries of the United States, none is entitled to higher rank than Thomas Blanchard, inventor of the tack-making machine, the machine for turning gun-stocks, that for making shoe lasts, of an improved process for bending timber, and of many other mechanical contrivances. An interesting sketch of Blanchard's life, written by Asa H. Waters, has recently been published for the purpose of vindicating for Blanchard his just place among American worthies, refused to him by certain historians of our national industries. Mr. Waters's pamphlet is a valuable contribution to the literature of invention, but he is certainly in error when he claims for Blanchard the credit of having originated what is known as the "uniformity system" in manufacture—the idea of making any number of perfectly uniform copies of the several parts of a piece of mechanism so that one copy may be interchanged with any other copy of the same part.

The origination of this idea is asserted by the author for Blanchard in the following terms: "This perfect uniformity of Blanchard's work" (with the gun-stock-turning machine) "suggested the idea of having all the parts of the guns made at the armories perfectly uniform, so as to be interchangeable" (p. 9). Again, same page:

"The War Department, impressed with the importance of having the guns so made that after a battle the broken ones could be readjusted, ordered the Springfield Armory