Within a few years several methods had been proposed by different inventors, but none was at first very successful, not from any fault in the principle, but because the effect of electrostatic capacity of the line was left out of account in the early arrangements.
Utilizing this principle many inventors have devised forms of electrostatic voltmeter.
Pick machines have also been introduced by Jones and Levick, Bidder, and other inventors, but their use is now mostly abandoned in favour of those working continuously.
He goes on to attribute the world's science and civilization to pagan inventors; but it is not clear whether in this he is alluding specially to the culture of his own city.
The mariner's compass during the early part of the 19th century was still a very imperfect instrument, although numerous inventors had tried to improve it.