Besides the works which we have mentioned, lie pub lished in 1677 his Lamjias, or Descriptions of some mechani cal improvements in lamps and water poises.
The most important of Dr Hooke's inventions, was un doubtedly the method of regulating watches by the balance spring, which has since his time been carried to the high est perfection. Huygens has commonly been considered as the author of this invention, but there is no doubt that Hooke had invented it about 14 years before. The post humous works of Dr Hooke, collected from his papers by Richard Waller, ecretary to the Royal Society, with a life of the author prefixed, were published in 1705. Another life of Hooke was published in Ward's Lives of the Gres ham Professors, p. 109. Loud. 1740. The papers which Hooke contributed to the Philosophical Transactions, will be found in volumes i. ii. iii. v. vi. ix. xvi. xvii. and xxii. of that work.
The following list of Dr Hooke's inventions is taken prin cipally from a MS. of the late Dr Robinson, professor of na tural philosophy in the university of Edinburgh.
1655. Hooke discovered that the barometer indicated changes in the atmosphere, and was connected with the weather. Before the year 1652 the same discovery was made by the Rev. Mr. Gregory of Drumoak. See our Life Of JAMES GREGORY.
1655. Contrived the clocltmakers' cutting engine.
1656. Contrived a 'scapement for the small vibrations of pendulums.
1656. Invented the spiral spring for regulating the vi brations of a watch balance.
1658. Contrived the Boileau) or double barrelled air pump.
1660. Used the conical pendulum for procuring a mi nute division of time.
1660. Explained capillary attraction by affinity.
1660. Found that the catenarian curve was the best form for an arch.
1663. Invented his marine barometer and sea gage, and also the method of supplying air to the diving bell.
1664. Invented a quadrant by reflexion, and a clock for registering the weather.
1664. Proposed the freezing of water in a fixed tempe rature; and in 1684 the boiling of water as another fixed point.
1664. Applied a screw for dividing astronomical instru ments.
1665. Proposed to find the earth's parallax by means of a zenith telescope, also by observing the moon in distant places, and in a solar eclipse.
1666. Nov. 28. Invented the spirit level.
1668. Proposed his theory of combustion. See his Ali crographia and Lampas.
1669. Proposed a pendulum, or a drop of water, as a standard measure. Proposed 'a camera obscura with a lamp.
1674. Invented the areometer.
1674. Tried the famous experiment with Newton on the inflexion of light.
1678. Proposed a steam engine on Newcomen's princi ple.
1679. Sheaved that the path of a falling body compound ed with the earth's motion is an ellipse.
1680. First observed the secondary vibrations of sound ing bodies; that a glass touched with a fiddle bow threw water into waves at four points, and that the fundamental sound was accompanied with its hat monies.
1682. Observed the separability of heat and light by a glass plate.
1687. Observed the rapid propagation of sound through solid bodies.
Hooke appears also to have been the first who explained the rise of vapour by a dissolving power in the air, and who took a just view of the arrangement of iron filings rotund a magnet. See IIEvEnus and HUYGENS.. (7r)