Thomas Ross was the son of Andrew Ross, a founding member of the Microscopical Society of London (later the Royal Microscopical Society) in 1839 and arguably the best microscope maker in Victorian England alongside Powell & Lealand and Smith & Beck. Among other inventions, Ross was the first to build lenses with a correction collar, which allowed correcting chromatic aberration depending on the thickness of the lenses used in the preparations. In 1859, after the death of his father, Thomas inherits the company and after 3 months he is elected a member of London society to replace Andrew. For a number of years he was a partner of J H Dallmayer, of whom he was a brother-in-law, and a large manufacturer of optics. In 1862 he presented his own model of it at the London International Fair. He maintained a certain prestige of the firm until in 1906 the business was transferred to "Swift & Son", whose founding member, James Swift, had been an employee of his father.
Extraordinary Ross-Zentmayer type microscope built around 1885 by Thomas Ross, son of the famous Andrew Ross with serial number 5356. The name of the model defines a set of microscopes characterized by allowing oblique illumination of the element to be analyzed. This type of design was very widespread in the US from 1870 and this particular one is surely the most famous. It is defined by the double pillar stand that secures the microscope to the base and was first designed by Jackson. High-end, it is very equipped with the necessary accessories for observations of different types. The mechanism of the observation subbase includes a condenser, filter holder and light regulator, as well as a mechanical platform with movements in the X-Y axes and rotating. It has 5 objectives, 3 of them built by T. Ross of 1/5, 1 and 2 inches and the other two with a correction collar, manufactured by Powell & Lealand. One of them has a built-in liebherkun to concentrate the light. Its appearance is impressive and it has a height of 56 cm.
References: G. Turner, "Great Age of the Microscope", pag 154-170
G. Turner, "Great Age of the Microscope", pag 162-163, Fig 155-156
G. Turner, Collecing Microscopes, pag 71
H. Moe, "The Story of the Microscope", pag 164-165, Collecing Microscopes, pag 71
Links: http://www.arsmachina.com/ross1302.htm
http://www.antique-microscopes.com/photos/rosszent.htm
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