He breathed deeply, more interested in detecting the faint smell of the warlord.
His gaze traveled over her face, detecting something that touched his mouth with a slight smile.
The imperfections of the thermopile, with which he began his work, led him, about 1880, to the invention of the bolometer, an instrument of extraordinary delicacy, which in its most refined form is believed to be capable of detecting a change of temperature amounting to less than one-hundred-millionth of a degree Centigrade.
ELECTROSCOPE, an instrument for detecting differences of electric potential and hence electrification.
Hertz then devised a wave detecting apparatus called a resonator.