Plate, shape of card used in escapement by Edward Kater Figure 4 showing the shape of a card used in creating the escapement for the astronomical clock. Subject: Astronomy / Scientific Instruments Published in Philosophical Transactions as 'Description of an escapement for an astronomical clock, invented by the late Captain Henry Kater, F.R.S. &c., drawn up from his own memorandums by his son Edward Kater, Esq. Communicated by Sir J. F. W. Herschel, Bart., K. H. V. P. R. S. &c'. Received from Kater on 22 March 1840. Communicated 25 March 1840. Received from Sir J F W [John Frederick William] Herschel on 26 March 1840. Read 30 April 1840. [1840]