On its completion he superintended the erection of the telescope, and had the honour of directing it to several of the celestial objects for the Queen and the Princess Alice, and answered their many interesting questions as to the stars and planets within sight.
Mr.Cooke was put to his mettle towards the close of his life.

A contest had long prevailed among telescope makers as to who should turn out the largest refracting instrument.

The two telescopes of fifteen inches aperture, prepared by Merz and Mahler, of Munich, were the largest then in existence.

Their size was thought quite extraordinary.
But in 1846, Mr.Alvan Clark, of Cambridgeport, Massachusetts, U.S., spent his leisure hour's in constructing small telescopes.[9] He was not an optician, nor a mathematician, but a portrait painter.

He possessed, however, enough knowledge of optics and of mechanics, to enable him to make and judge a telescope.