afford it, and Sheffield plate, silver-plated copper, for those less well off. Boulton and his father make small silver items throughout the 18th century, and there is no record of large items in either silver or Sheffield plate being made in Birmingham before Boulton does so. To make items such as candlesticks more cheaply than the London competition, the firm makes many items out of thin, die-stamped sections, which are shaped and joined together. One impediment to Boulton's work is the lack of an assay office in Birmingham. The silver toys long made by the family firm are generally too light to require assaying, but silver plate has to be sent over 70 miles (110 km) to the nearest assay office, at Chester, to be assayed and hallmarked, with the attendant risks of damage and loss. Alternatively they can be sent to London, but this exposes them to the risk of being copied by competitors. Boulton writes in 1771, "I am very desirous of becoming a great silversmith, yet I am determined not to take up that branch in the large way I intended, unless powers can be obtained to have a marking hall [assay office] at Birmingham." Boulton petitions Parliament for the establishment of an assay office in Birmingham. Though the petition is bitterly opposed by London goldsmiths, he is successful in getting Parliament to pass an act establishing assay offices in Birmingham and Sheffield, whose silversmiths face similar difficulties in transporting their wares. The act is passed in March 1773, to grant Birmingham and Sheffield the right to assay silver. 1773: The Birmingham Assay Office opens on 31 August and the town becomes a leading manufacturer of all types of silver ware spanning three centuries. The Assay office can still be visited today by appointment and is situated near to the city's well renowned Jewellery Quarter. 1793: "A gentleman of the name of Hand" in Birmingham obtains a patent for preparing flexible leather having a glaze and polish that renders it impervious to water and needing only be wiped with a sponge to restore it to its original lustre. This is later recognised as patent leather and is further improved by other inventors. At some time around the late 18th or early 19th century a stand-alone cooking range or stove is invented by John Heard (joiner), capable of roasting, boiling, baking and of course heating a room. The