Background
Thomas Melvill was born in 1726, in Monimail, Fife, United Kingdom to the family of the Reverend Andrew Melville, minister of Monimail and Helen Whytt. He is the younger brother of Robert Melville, an army officer.
University Ave, Glasgow G12 8QQ, United Kingdom
Thomas Melvill studied at the University of Glasgow and received his Master of Arts degree in 1744. He studied divinity there in 1748 and 1749 and acquired a taste for experimental philosophy from Alexander Wilson, his landlord and later the first professor of astronomy at Glasgow University.
University Ave, Glasgow G12 8QQ, United Kingdom
Thomas Melvill studied at the University of Glasgow and received his Master of Arts degree in 1744. He studied divinity there in 1748 and 1749 and acquired a taste for experimental philosophy from Alexander Wilson, his landlord and later the first professor of astronomy at Glasgow University.
Astronomer meteorologist physicist scientist
Thomas Melvill was born in 1726, in Monimail, Fife, United Kingdom to the family of the Reverend Andrew Melville, minister of Monimail and Helen Whytt. He is the younger brother of Robert Melville, an army officer.
Thomas Melvill studied at the University of Glasgow and received his Master of Arts degree in 1744. He studied divinity there in 1748 and 1749 and acquired a taste for experimental philosophy from Alexander Wilson, his landlord and later the first professor of astronomy at Glasgow University.
Together with Alexander Wilson, Melwill used kites to investigate the change in atmospheric temperature with altitude. Melvill studied Newton’s Opticks closely. In a paper “Observations on Light and Colours,” given to the Medical Society of Edinburgh on 3 January and 7 February 1752, he wrote of his use of a prism for examining color in flames. The property of common salt, whereby it turns a flame yellow, was probably well recognized, but Melvill was seemingly the first to treat the coloration in any way quantitatively. He studied the spectrum of burning alcohol into which he introduced in turn sal ammoniac, potash, alum, niter, and sea salt, noting the persistence of the yellow component of the spectrum, and he remarked that this yellow color was of a definite degree of refrangibility. His work appears to have had little influence, and the origins of spectrum analysis are not usually traced back before W. H. Wollaston’s discovery of dark solar lines (1802).
Thomas Melvill belonged to one of the Protestant denominations of Scotland.
Thomas Melvill noted the yellow spectrum of sodium and considered a means of testing a suggested the relation between the velocity of light and its color.
As an explanation of the different refrangibilities of light of different colors, in terms of the corpuscular theory, Melvill suggested that the several colored rays were projected with various velocities from the luminous body - the violet with the least. A letter to Bradley, written from Geneva, dated 2 February 1753, and read to the Royal Society on 8 March 1753, pointed out an interesting consequence regarding aberration. Depending on velocity, the aberration would be different for different colors, and the satellites of Jupiter would gradually change color in one way (white to violet) on entering the planet’s shadow, and another way (red to white) on leaving the shadow. This effect was not observed, and the suggestion was soon forgotten. Its originality is in some doubt, since Courtivron’s Traité d’optique, published in 1752 and readily available to Melvill in Geneva, contained not only the fundamental hypothesis but its consequences for the appearance of Jupiter.
Melvill developed the idea further in a letter of 2 June 1753 and suggested that Bradley’s observations of aberration revealed the ratio of the velocities of light, not in space and air, but in space and in the humors of the eye. He believed that it would be necessary to reject what he called “Sir Isaac Newton’s whole doctrine of refraction by an accelerating or retarding power,” if the consequences of his new hypothesis were not confirmed. Dying at the age of twenty-seven, he scarcely lived long enough to be disappointed at the neglect of his letter, which contains essentially the same idea as that adopted by Alexander Wilson’s son, Patrick, who long afterwards discussed the consequences for an observer with a water-filled telescope. Conclusions drawn by Wilson and Robison were put to the test by Arago and communicated to the Institut de France in 1810.
At the close of his second letter to Bradley, Melvill stated that he had designed and had made in Geneva a timepiece with a conical pendulum, the virtues of which he extolled.
There is no information on whether Thomas Melvill was ever married or had any children but supposedly not based on his relatively young age at death.