Date of Birth: 
About Henry Joseph Grayson
- Henry Joseph Grayson (9 May 1856 – 21 March 1918) was a British-born Australian nurseryman and scientist, best known as the designer of a machine for ruling diffraction gratings. Grayson was born in Worrall, near Sheffield, Yorkshire, England, son of Joseph Grayson, a Master Cutler, and his wife Fanny, née Smith.
- Grayson came of a family of market gardeners, and travelled to New Zealand in the early 1880s.
- After returning to England and marrying Elizabeth Clare on 11 August 1886, the couple soon migrated to Victoria (Australia) where Grayson worked as a nursery gardener.
- Becoming interested in science he joined the Field Naturalists Club of Victoria, studied botany and did some work on the diatoms, a group of minute plants.
- Grayson attended meetings of the Royal Microscopical Society and developed a talent for preparing microscope slides.
- Before 1894 he had constructed a machine for making micrometer rulings on glass, the results being very good for that time.
- In 1897 some very beautiful work Grayson had done in cutting sections of plants led to his being given a position in the physiology department of the University of Melbourne under Professor C.
- J.
- Martin. He was afterwards transferred to the geology department, and in December 1901 accompanied Professor F.
- T.
- Gregory on his expedition to Central Australia.
- In the preface to The Dead Heart of Australia Gregory paid a special tribute "To my assistant Mr Grayson on whom much of the hard work of the expedition fell".
- In 1910 Grayson was associated with Daniel James Mahony in the preparation of a paper on "The Geology of the Camperdown and Mount Elephant Districts" (No.
- 9 in the Memoirs of the Geological Survey of Victoria), and in the same year, while working at the university under professor E.
- W.
- Skeats, who succeeded Gregory, Grayson made a highly efficient apparatus for preparing rock sections, a description of which will be found in the Proceedings of the Royal Society of Victoria for the year 1911.In the meanwhile Grayson had been perfecting his fine ruling work.
- Grayson had by then succeeded in creating 120,000 diffractions lines to the inch (4,700 lines per mm).
- Grayson described his work on diffraction ruling in a report published for the Report of Meeting, Eighth Meeting of the Australasian Association for the Advancement of Science, held at Melbourne, Victoria in 1900: The apparatus I first devised and used was exceedingly simple in principle, and consisted essentially of a fine steel screw and wedge of glass, the incline of the latter bearing some definite ratio to the pitch of the former.
- This glass wedge traveled along a bed, or base plate, also of glass, being kept in position by means of a slot cut along its surface.
- As the wedge was propelled forward by the screw it raised a vertical plate, accurately adjusted at right angles to the base plate, and a free as possible from movement other than that imparted to it by the wedge.
- To this vertical plate the slide, or disc to be ruled upon, was attached by means of a suitable cement.
- A platform for a sliding diamond carriage, bridged the base-plate and wedge at a suitable height, being of course, arranged transversely to and in front of the vertical slide. From this time onwards much of his time was given to the preparation of a dividing engine for ruling diffraction gratings.
- Grayson was transferred to the Natural Philosophy department of the university under Professor T.
- R.
- Lyle in 1913 and was allowed to give his full-time to the machine.
- In July 1917 he read a paper before the Royal Society of Victoria giving a full description of the machine, which was published with several plates in the society's Proceedings for that year.
- In the same year Grayson was awarded the David Syme Research Prize of £100 by the University of Melbourne.
- Grayson died in Clyde of heart disease leaving a widow but no children.
Read more at Wikipedia