Printed pamphlet entitled 'Observations on the Principle and Use of the New Patent Sea Log and Sounding Machine, Invented by Edward Massey, of Hanley, Staffordshire', with an engraving of the two machines. The pamphlet was printed in Liverpool and includes a preface in the form of a letter addressed from Smith to Robert Bill, Esquire, in which he describes the invention as 'one of the most important ever offered to the public' [RGO 14/31: 16-17].
It begins with observations on the patent log [RGO 14/31: 18-22] followed by observations on the sounding machine [RGO 14/31: 22-31r], and also includes letters of recommendation from merchants and masters of vessels who had made trial of the patent machines, including Joseph Whittle, Captain William Killey, Lieutenant and Commander Philip Brown, Thomas Mullion, William Neilson, John Tobin, Thomas Fletcher, Thomas & John Moss, John Bolton, Thomas Bennett and John Murphy [RGO 14/31: 31v-35].