“They (telescopes) cannot be so formed as to take away that confusion of Rays wich arise from the Tremmors of the Atmosphere.
The only Remedy is a most serene and quiet Air, such as may perhaps be found on the tops of the highest mountains above the grosser clouds”
So hypothesised Newton in “Opticks” in 1704.
However, despite the passage of over 150 years no one had checked the veracity of this theory.
In 1856 Charles Piazzi Smyth changed all this by securing a grant of £500 from the Admiralty to perform a suitable experiment.
He chose Tenerife as a good place – much closer to the Equator than Britain and having suitably high mountains. He took several instruments with him and performed experiments initially at a height of 8,900 feet at Guajara and then, later, at a height of 10,700 feet at Alta Vista.
He experimented mainly with double stars as a way of seeing how well they could be resolved at altitude and he published the following images, drawn by himself, of a double star, α Piscium (above).
On the left, an image of the double star as seen near sea level in Scotland, and on the right the same star as viewed at Alta Vista. Together with other data collected by Piazzi Smyth it is a stunning demonstration of how right Newton had been.
Dr Bruce Vickery