References to this clock are frequent in the records of the Royal Society--being mainly periodic injunctions to Hooke to get on with the work--until its completion in May 1679. The description which Hooke was asked to supply was subsequently found among his papers and printed by William Derham as follows:[9] The weather-clock consists of two parts; _first_, that which measures the time, which is a strong and large pendulum-clock, which moves a week, with once winding up, and is sufficient to turn a cylinder (upon which the paper is rolled) twice round in a day, and also to lift a hammer for striking the punches, once every quarter of an hour. _Secondly_, of several instruments for measuring the degrees of alteration, in the several things, to be observed. The first is, the barometer, which moves the first punch, an inch and half, serving to shew the difference between the greatest and the least pressure of the air. The second is, the thermometer, which moves the punch that shews the differences between the greatest heat in summer, and the least in winter. The third is, the hygroscope, moving the punch, which shews the difference between the moistest and driest airs. The fourth is, the rain-bucket, serving to shew the quantity of rain that falls; this hath two parts or punches; the first, to shew what part of the bucket is fill'd, when there falls not enough to make it empty itself; the second, to shew how many full buckets have been emptied. The fifth is the wind vane; this hath also two parts; the first to shew the strength of the wind, which is observed by the number of revolutions in the vane-mill, and marked by three punches; the first marks every 10,000 revolutions, the second every 1,000, and the third every 100: The second, to shew the quarters of the wind, this hath four punches; the first with one point, marking the North quarters, viz. N.: N. by E.: N. by W.: NNE.: NNW.: NE. by N. and N.W. by N.: NE. and N.W. The second hath two points, marking the East and its quarters. The third hath three points, marking the South and its quarters. The fourth hath four points, marking the West and its quarters. Some of these punches give one mark, every 100 revolutions of the vane-mill. The stations or places of the first four punches are marked on a scrowl of paper, by the clock-hammer, falling every quarter of an hour. The punches, belonging to the fifth, are marked on the said scrowl, by the revolutions of the vane, which are accounted by a small numerator, standing at the top of the clock-case, which is moved by the vane-mill.