The foolscap folio ledgers are uniformly bound in half suede and cloth (with the letters A and B respectively on the spines); the covers show signs of wear, but the volumes are very sturdy, with the contents in excellent condition. The first one contains 21 pages of index and 102 pages of the ledger proper. Each page is designed to record the details of nine patients; the last entry is numbered 916. The data are the name of the patient, often the address, the date of the consultation, the referring doctor, the prescription for the lens for each eye, and more often than not, specific details of the spectacle lenses or frames. Examples of the latter include 'pale blue periscopic lenses / gold frame / twisted curled sides'; 'Gold Pince-nez, Canadian'; 'pantoscopic frame'; and 'Extra small Children's frame made to order'. The first entry is dated 20 October 1886. Initially, business was not brisk; the fifth entry was not for another eleven weeks, on 7 January 1887, when no less an individual than William Austin Horn presented himself. By the time this volume ends on 15 July 1892, a host of still-familiar Adelaide family names had made an appearance: Verco, Goyder, Hawker, Hack, Fowler, Woods, Bagshaw, Magarey, Jury, Mead, Rischbeith, Morphett ... The second volume is more of the same: there are 39 pages of index, 298 pages of the ledger proper, with each page containing details of seven patients (approximately 2086 individual records). This volume commences on 16 July 1892 (the day after the first volume ends), and the last page is reached on 19 December 1894. The invoices are chronologically arranged in a contemporary quarter cloth and marbled papered boards post-binder; both covers are detached, with minor signs of use and age, and there are some chipped edges to the contents, but overall, it is a fascinating collection of unique records documenting a highly specialised profession in colonial Australia. An obituary of Otto Boettger (1842-1907) appeared in 'The Chronicle' (Saturday 7 September 1907): 'The death occurred at Cologne recently of Mr. Otto Boettger, the well-known Adelaide optician and instrument-maker. The deceased, who was 65 years of age, was born in Elberfeldt, Germany, and came out to Australia in 1877. He had previously conducted a large business in St. Petersburg, but the venture not proving successful, he determined to emigrate to Adelaide. His first engagement was with Mr. Dobbie [Alexander Williamson Dobbie, 1843-1912, a successful local engineer and inventor] cleaning old keys and repairing machinery. Starting in business for himself, his great knowledge of surveying and engineering instruments led the Government to place all their work in this department in his hands, and the results proved eminently satisfactory. About 10 years ago the business in Flinders-street was transferred to Mr. G.C. Kohler, who was an apprentice of Mr. Boettger's at one time, and had been with him nearly 30 years. Mr. and Mrs. Boettger then returned to Germany to spend the remainder of their lives in retirement'. Another local newspaper, 'The Register', records details of an overseas trip Boettger made in 1894. He left Adelaide for Europe on 11 April 1894 (see the report of the Valedictory Dinner on 2 April in the newspaper the following day). His return is reported on 13 December: 'Among the passengers who returned to Adelaide by the German mail steamer "Habsburg" on Wednesday was Herr Otto Boettger, the well-known optician and maker of scientific instruments. He went to Europe for the purpose of seeing what is at present being done in the large cities in optical matters, and returns in very good health. To a representative of the "Register" who saw Herr Boettger on board the mail steamer he gave a few particulars of his enquiries. "You must know," he began, "that until the last few years it was not possible to get made to order astigmatic lenses, either here or in any of the other colonies. I am glad to say that the plan I had followed is, in all essential points, the same as I have seen in the best optical workshops in London, Berlin, Paris, and Birmingham. The difference is merely in the speed, because in these large centres there is so much to be done. I was glad to find that in the matter of accuracy of curve and perfection of finish the lenses turned out in Adelaide are not inferior to any I have seen. There has been considerable advance made in the construction of all sorts of scientific instruments, and I have been much interested in examining all the latest improvements'.