R. ACKERMAN, 191, Regent-street, W. L. BARBE, 60, Quadrant, Regent-street, W. J. BARNARD, 339, Oxford-street, W. Messrs. BRODIE & MIDDLETON, 79, Long-acre, W.C. H. MILLER, 56, Long-acre, W.C. J. NEWMAN, 24, Soho-square, W. Messrs. REEVES & SONS, 113, Cheapside, E.C. Messrs. ROBERSON, 99, Long-acre, W.C. Messrs. ROWNEY & CO., 51, Rathbone-place, W. Messrs. SHERBORNE & TILLYER, 321, Oxford-street, W. Messrs. WINSOR & NEWTON, 38, Rathbone-place, W. From each of the above-mentioned firms I have obtained valuable information, and from several, excellent samples of their products. I am glad, therefore, to take the present opportunity of expressing my obligations to them. From Messrs. Winsor & Newton, especially, I have received the kindest and most intelligent co-operation; and I am happy to be the channel of making public the results of a series of experiments, on the combinations of colours and the use of various materials for illuminating purposes, suggested by me, and made with great tact and judgment by Mr. W. H. Winsor. Messrs. Winsor & Newton and Mr. Barnard have, up to the present time, done most to smooth away the difficulties which beset the illuminator. Messrs. Newman, Messrs. Rowney & Co., Messrs. Reeves & Sons, and Mr. Barbe, have also recently contributed valuable improvements or special adaptations.[115] The colours best suited for illuminating I believe to be as follows:-- B Lemon Yellow } A Gamboge } Yellow. A Cadmium Yellow } D Mars Yellow } B Rose Madder } A Crimson Lake } C Carmine } Red. C Orange Vermilion } A Vermilion } A Cobalt } A French Blue } Blue. D Smalt } D Mars Orange } Orange. B Burnt Sienna } C Burnt Carmine } Purple. D Indian Purple } A Emerald Green } Green. C Green Oxide of Chromium } B Vandyke Brown Brown. A Lampblack Black. A Chinese White White.