The best enamellers were to be found in London, engaged in enamelling the porcelain of Bow and Chelsea; but it soon became obvious that enamellers were wanted in the Staffordshire potteries also. It was again two Dutchmen who initiated into this art the native potters of Staffordshire. They probably knew the Warburtons and set up their enamelling ovens near them in Hot Lane.[64] Here they worked and attempted to keep their art secret, with the usual result of attracting special attention. Their stoves, their mixtures and their temperatures soon became public property, and a regular enamelling industry was soon established round Hot Lane. It is said to have been Ralph Daniel, the man who had brought the secret of plaster of Paris moulds from Paris, who did most to develop enamelling.[65] He imported workmen from London, Bristol and Liverpool, and soon after 1750 the enamelling of earthenware and salt glaze became a Staffordshire industry. Among enamellers too should be mentioned a Shelton potter, Walter Edwards, who was chemist and enameller as well as potter. He had as partner the Rev. John Middleton, curate of Hanley from 1737-1802, but Edwards, unlike the curate, died young in 1753, leaving a book full of receipts for glazes and enamels. The difficulty always was to get metallic oxides which would stand heat. From an artistic point of view they had much better have left their salt glaze plain white, or drab, or uniformly tinted by a slip dip. The salt-glaze body compared with Chinese porcelain; their painting did not compare with Chinese painting, or only compared in an unfortunate sense for Staffordshire. Earthenware, being made for use, had less decoration, and what it got was less gaudy and more suited for serviceable articles. [Illustration: Enamelled salt glaze jug, probably by Baddeley of Shelton, dated 1760. From the Stoke-on-Trent Museums. The jug was a presentation piece from the Rev. J. Middleton, who was a partner with the above Baddeley.] There was however one very successful, or at least artistically successful, manner of colouring the salt glaze. It was practised by William Littler and Aaron Wedgwood (1717-1763), two brothers-in-law who about 1740 were making salt-glaze pottery at Brownhills. Taking a hint from Astbury, they dipped their ware in a bath of carefully lawned slip, so as to gave it a smooth surface before firing. In this slip they proceeded to put cobalt, which gave a beautiful uniform blue to the whole piece, and this smooth blue body, under the salt glaze, acquired a tint of great brilliance. On the strength of Shaw’s account of this process,[66] many writers have mistakenly attributed to William Littler and Aaron Wedgwood the first introduction of liquid glazes, but it is quite clear, as Mr Burton has pointed out, that this was no leaded blue glaze, but a blue slip subsequently glazed with salt.[67]