One of many famous machine tool makers based in Keighley, Yorkshire, England, Darling & Sellers had their factory in Lawkholme Lane. Founded in 1854 as a partnership between three men, Charles Brown, William Darling and Robert Sellers (all of Keighley) the firm was first described as "Engine and Machine Tool Makers", Mr Brown was soon to step aside and the company renamed Darling & Sellers.
In 1861 the firm was listed as employing just six men and twelve boys and, by 1866, described in trade directories as "Tool Makers of Airedale Works". By 1871 employee numbers had risen to 38 and, ten years later, a move had been made to their final home in Lawkholme Lane where their trade description was simply "Tool makers".
Following this, expansion was considerable and, in 1896, it was necessary to raise money by expanding the shareholding and become a limited liability enterprise, Darling & Sellers Ltd. - now described as engaged "...in the business of engineers, machinists, machine tool manufacturers, ironfounders and merchants". The first directors were John W. Darling and Albert Darling - each remunerated at the rate of £2 : 10s : 0d. each per week - with Herbert Sellers on £2 : 0s : 0d and Arthur Sellers paid a mere £1 :10s : 0d. In 2022 these wages, allowing for inflation, would have bought good worth just £354 to £210 - so, presumably, dividends, expenses and bonus payments must have been rather more generous.
As soon as the company was established in its new factory, a very wide variety of machines began to emerge that was eventually to include lathes of conventional, sliding gap and extra heavy-duty; horizontal borers; planers; plano-millers (planers fitted with motor-driven cutters in place of fixed cutting tools); plano drills; vertical, horizontal and universal milling machines; slotters; spur and bevel gear cutters; radial-arm drills and moulding machines, a situation that continued until the mid-1930s when a change was made to concentrate on lathes. 
Nothing that Darling & Sellers made could be classed as lightweight; everything was of massive construction and intended for serious, professional engineering. By the early 1900s, the range of lathes included seven conventional types with centre heights from 7 to 12.5 inches - with a choice of either cone-pulley or all-geared headstocks - and four models of relieving lathes with centre heights from 8 to 12.5 inches.
In 1950 Darling and Sellers was absorbed into a machine tool group that comprised D. Mitchell and Co., Ltd. of the Central Ironworks, Parson Street, Keighley, and Rushworth and Co. of Sowerby Bridge. An extract from a publication of the time stated, "Following completion of existing commitments, production of the "Mitchell" 10 1/2in. and 16 1/2in. centre lathes is to be stepped-up, which will mean doubling the existing staff. New plant is already being installed while the factory is to be modernised and will include a canteen and other welfare amenities. The newly-appointed directors are Messrs. P. Leslie Crabtree. John W. Rushworth, C. Donald Rushworth and Sidney Wilson." In 1967 the entire enterprise was taken over by the B. Elliott and Co. Group and, by the 1950s, it appears that the sole remaining lathe branded as a Darling and Sellers was a very heavy, 10.5" x 74" -inch model that weighed 3.5 tons and with the facility to control the headstock from the carriage. Full details are shown below.