Word: seismographic
(lookup in dictionary)
(lookup stats)
Dates: all
Sort By: most recent first
(reverse)
Four members of the Faculty of Arts and Sciences have received promotions, University authorities announced yesterday. Among those elevated is L. Don Leet '30, Director of the Seismograph Station at Harvard, Massachusetts, who has been made a full professor of Geology...
...rescue of these campanies has come L. Don Leet, associate professor of Geology and director of the University seismograph station. Leet has spent 15 years in research on the intensity of vibrations and the damage that they...
Leet has found that most of the vibrations in the ground and in buildings come from sources that people do not expect, and the majority of industrial detonations produce tremors too small to do any damage to nearby dwellings. By use of a relatively new instrument, the Leet Portable Seismograph, actual measurements of the intensity of industrial vibrations at varying distances from their source have been made. The net result has been of great value to the blasting companies and quarry-owners who, up to the present, had not known just how much damage their blasts have done...
Some startling facts have been brought to light through Leet's seismograph tests. In order to break window glass by concussion, charges must be fired in the open air, a most impractical thing in quarrying operations. Window glass must be subjected to pressures of 1 1/2 lbs. per square inch to break it, whereas air pressure at a few hundred feet from a quarry blast are 1 to two-thousandths of a pound per square inch, the same as those produced by a light summer breeze...
...other breaks that appeared this week were quickly tracked down and brought under control, with some being traced to leaky valves and others to the mains themselves. The city fathers have attributed the epidemic to a mysterious earthquake that has not been picked up by the University seismograph...