Euro 1.19 ap
This stamp shows the great telescope of William Lassell, set up in Malta between 1861-1865, against a background of stars showing nebula M42, which Lassell himself observed on various occasions from Malta.
William Lassell was born in Bolton in 1799. He was a brewer by profession but used his fortune to build an observatory at Starfield near Liverpool. He equipped this observatory with a 24-inch reflector telescope. Like many other astronomers he ground the mirrors himself - this was considered a very delicate and laborious task in the astronomical field, but in contrast to others he pioneered an equatorial mount of his telescope for easy tracking of celestial objects as the Earth rotates. Soon enough discoveries started to be made.
On 10 October 1846 he discovered Triton, a satellite of the planet Neptune. Other spectacular results were announced when Lassell discovered Hyperion, the moon of the planet Saturn and the satellites Ariel and Umbriel of the planet Uranus. Since even in those days light pollution in Liverpool hampered his observation of the night sky, and since Lassell’s main observational interest was the outer planets, he decided that the clear skies of Malta would successfully enable him to continue his work.
William Lassell first visited Malta in 1852 and soon shipped his sixty-one centimetre diameter telescope which measured six metres in length to our island. This telescope, which was already an achievement in design and performance, was stationed on St.John Cavalier in Valletta. This was followed in 1861 by a 1.2 metre diameter telescope which had a length of 11.3 metres. This telescope was also built and shipped from Liverpool and was mounted at Tigné Barracks in Sliema.
This instrument, the world’s largest telescope of its kind at the time, was a Newtonian reflector. Its tube was made of an iron lattice with ribs fitted at equidistant spaces. This design was suitable to compensate and stabilise expansions due to the difference in internal and external temperatures of the telescope.
To be able to operate his telescope a wooden tower with a built-in stair case was constructed adjacent to it, to give Lassell the space he needed to make his observations at any desired position. This telescope was driven by two Maltese workmen with the aid of gear wheels which had to be operated by hand. William Lassell collaborated with Albert Marth who was a professional astronomer in Ireland and amongst Lassell’s discovies from his gigantic telescope in Sliema, are six hundred nebulae and the variable star ‘S’ Pegasi.
When Lassell returned to England in he offered his reflector telescope to other observatories but in spite of its excellent quality it was finally broken up for scrap in 1877. This marked the end of an era.
Lassell died in 1880. Ten years before William Lassell had been elected president of the Royal Astronomical Society and the University of Cambridge had awarded him with the honorary LL.D. degree.
Two moon craters were named after Marth and Lassell. William Lassell's crater is found adjacent to Mare Nubium and Albert Marth's crater is situated near the edge of Mare Humorum. In December 1975 a road in Fgura was named after William Lassell.

REFERENCES:
Proceedings of History Week. (1981)(108-109) William Lassell:— Observations of Plantes and Nebulae at Malta — Public Lib.
William Lassell:— Lettera sulla Nebula Planetaria — Public Lib.
Despatches from Secretary of State to H.E. Sir J. Gaspard Le Merchant, Governor of Malta (1861).
Monitore Geografico Scientifico di Malta (Ottobre 1887) — Public Lib.
Malta Govt. Gazette — 12/12/75.