Galilean moons century when other inner moons were discovered, and Marius' names became widely used. Galileo was able to develop a method of determining longitude based on the timing of the orbits of the Galilean moons. The times of the eclipses of the moons could be precisely calculated in advance, and compared with local observations on land or on ship to determine the local time and hence longitude. The main problem with the technique was that it was difficult to observe the Galilean moons through a telescope on a moving ship; a problem that Galileo tried to solve with the invention of
Electric instrument Electric instrument An electric musical instrument is one in which the use of electric devices determines or affects the sound produced by an instrument. Electric musical instruments are an example of electric music technology. It is also known as an amplified musical instrument due to the common utilization of an electronic instrument amplifier to project the intended sound as determined by electric signals from the instrument. Two common types of instrument amplifiers are the guitar amplifier and the bass amplifier. This is not the same as an electronic musical instrument, like a synthesizer, which uses entirely electronic means to both