Volume entitled ‘Solar Spherical Scale for Sketching’, dated May 1881, Naples, containing a number of diagrams and sketches., 1881., Adv.MS.50.7.3. Correspondence and papers, including many manuscripts in Gaelic, journals and yearbooks (with many photographs), albums of watercolour paintings and sketches, and experimental notebooks, of John Francis Campbell of Islay (1821-1885), Gaelic scholar and collector of oral tradition, traveller, scientist, official of the royal household and public servant., Adv.MSS.50.1.1-51.2.7. National Library of Scotland Archives and Manuscripts Division. https://manuscripts.nls.uk/repositories/2/archival_objects/16850 Accessed May 11, 2024.