1794. Also in the SLPS collection are letters to Henry Clifton Sorby, the Sheffield geologist, over the period 1844 - 1896. Hunter Archaeological Society Correspondence and diaries of Mrs Margaret Gatty and her daughter, Mrs Juliana H. Ewing, form part of the Hunter Archaeological Society's collection. Both were writers of children's books and Mrs Gatty did interesting work on algae; her correspondence includes letters from authorities in this field and Mrs Ewing's includes letters written by her from Fredericton in Canada and her correspondence with Randolph Caldecott, illustrator of her books (many of his adorned with pen and ink sketches). The period covered is 1830 - 1885. Clarke family of Noblethorpe Industry (particularly coal mining) and landowning naturally go together in many other family archives. Notable in this category are the Clarke family of Noblethorpe's estate and colliery records. This family worked some of the best Silkstone coal in South Yorkshire. Cumulatively their papers give a good picture of the coal trade as carried on by canal and the changeover to rail. Crewe Muniments Among the many collections of South Yorkshire deeds may be mentioned the Crewe muniments, including Bawtry deeds of the Lister family with references to wharves and trade on the river Idle. Business records The rich industrial history of the Sheffield area is represented in the large collections of business records, which cover iron and steel, silver plate, coal mining and cutlery firms to professional firms of solicitors, land surveyors, auctioneers and architects. Many of the city’s major industrial concerns have deposited their archives at Sheffield, notably: The firm of Thomas Bradbury and Sons, silver platers, is represented by day books, ledgers, orders, correspondence, etc., going back to the 1780s. A particular feature of this collection is the fine series of early engraved catalogues of old Sheffield plate. A collection of 29 massive ledgers of the South Yorkshire and North Derbyshire iron trade carried on by the syndicate of iron-masters of whom William Spencer was one, links up with material in the Spencer Stanhope collection. It was deposited by the Staveley Iron Works and covers the period 1690-1766. The ledgers give detailed information of many aspects of the iron trade and were unknown to Dr A. Raistrick when he wrote 'The South Yorkshire ironmasters, 1690-1750' (Economic History Review, 1939). There is also one volume of Staveley furnace accounts, 1772-1806. The nail and file trade in Sheffield is