He informs us that the clock is made of wood throughout, excepting the escapement and the dial, which are made of brass.

It bears the mark of "John Harrison, 1713." [5] Harrison's compensation pendulum was afterwards improved by Arnold, Earnshaw, and other English makers.

Dent's prismatic balance is now considered the best.
[6] See Mr.Folkes's speech to the Royal Soc., 30th Nov., 1749.
[7] No trustworthy lunar tables existed at that time.

It was not until the year 1753 that Tobias Mayer, a German, published the first lunar tables which could be relied upon.

For this, the British Government afterwards awarded to Mayer's widow the sum of 5000L.
[8] Sir Isaac Newton gave his design to Edmund Halley, then Astronomer-Royal.