Letter from [Henry James] Chaney, Board of Trade (Standards Department), 7 Old Palace Yard, to the Secretary of the Royal Society Regarding an expansion apparatus designed by Mr G F Rodwell, and made by the Cambridge Scientific Instrument Company. The apparatus has not been described in an any printed papers and differs from Rodwell's first apparatus 'for determining the rate of expansion by heat of solid bodies'. Enclosed is a not describing the new apparatus. An enclosed additional note remarks: 'For description which accompanied application (Apl. 1882) see Application Book I, 432. In his application for renewal of grant (Apl. 1883) he says this instrument is now nearly complete. See Appl Bk. I. 508.' 15 March 1886