SEARCH
0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
Prev | Current Page 156 | Next

Munro, John, 1849-1930

"Heroes of the Telegraph"


Employing a staff of skilful assistants to develop many of his ideas,
Dr. Siemens was able to produce a great variety of electrical
instruments for measuring and other auxiliary purposes, all of which
bear the name of his firm, and have proved exceedingly useful in a
practical sense.
Among the most interesting of Siemens's investigations were his
experiments on the influence of the electric light in promoting the
growth of plants, carried out during the winter of 1880 in the
greenhouses of Sherwood. These experiments showed that plants do not
require a period of rest, but continue to grow if light and other
necessaries are supplied to them. Siemens enhanced the daylight, and, as
it were, prolonged it through the night by means of arc lamps, with the
result of forcing excellent fruit and flowers to their maturity before
the natural time in this climate.
While Siemens was testing the chemical and life-promoting influence
of the electric arc light, he was also occupied in trying its
temperature and heating power with an 'electric furnace,' consisting of
a plumbago crucible having two carbon electrodes entering it in such a
manner that the voltaic arc could be produced within it. He succeeded
in fusing a variety of refractory metals in a comparatively short time:
thus, a pound of broken files was melted in a cold crucible in thirteen
minutes, a result which is not surprising when we consider that the
temperature of the voltaic arc, as measured by Siemens and Rosetti, is
between 2,000 and 3,000 Deg.


Pages:
144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168