HANSEN

56pp., foolscap 8vo. Stapled into brown printed wraps. Good, on lightly-aged paper. Includes sections on 'Results of field trials' and 'New developments and proposals'. Two appendices: 'Specifications of the NTSC, SECAM and PAL systems' (pp.46-50) and 'New documents received by the Ad-hoc Group' (pp.51-56). Scarce: no copies on OCLC WorldCat or COPAC. From the Pat Hawker archive.

11 + [1] pp., foolscap 8vo. Figure and two tables in text. Stapled into brown printed wraps. Very good, on lightly-aged paper. Uncommon: OCLC WorldCat lists copies at the British Library, Library of Congress, Hanover and the German National Library. From the Pat Hawker archive.

31 + [1] pp., foolscap 8vo. Describes the features of Ampex Instavideo; AVCO Cartrivision; EVR Partnership EVR; Nordmende Colorvision; Philips VCR; Sony Videocassette; Teldec Videodisc; Vidicord; and other proposed systems. Illustrations and table in text. Stapled into brown printed wraps. Good, on lightly-aged paper, with initials on front cover. Scarce: no copies on OCLC WorldCat or COPAC. From the Pat Hawker archive.

On three pages of a foolscap bifolium, supplied by J. Warner & Co., Law Stationer of New Oxford Street, ruled and with red borders. Good, on lightly stained paper. On 25 July 1912 Mohr and Friedrich Hansen 'made an application for a Patent for an improvement in the process of the manufacture of a filament for an electric incandescent lamp (at present known as the "Boran Lamp") accompanied by a complete specification at the Patent Office', but the application has not yet been accepted.