Diagram, floating collimator by [Henry Kater?] Plate 13 showing a diagram of Henry Kater's floating collimator, designed to replace the use of a plumb-line in astronomical observations. Inscribed with publication and plate details. Not signed. Royal Society stamp verso. The manuscript for this paper is wanting. Subject: Scientific Instruments Published in Philosophical Transactions as part of paper titled 'The description of a floating Collimator' by Henry Kater. Read to the Royal Society on 13 January 1825. [1825]