Cracking the mirror

FIELD OF VIEW

A great many lunar craters, asteroids and comets have been named after either their discoverer or, as an honorary gesture, those involved in a field of corresponding scientific work. Literally thousands of human names are scattered across the heavens, and a considerable proportion of the objects need an optical aid to view them. But when it comes to these astronomical instruments, only a handful bear a person’s name.

Imagine, if you will, a curtain rising to reveal a theatre stage with a cast of players, all about to relate events in a remarkable one-off drama that concludes with the ‘first light’ of one such astronomical instrument, the Newtonian telescope. Just like stumbling across the faint image of a distant comet that was to become a spectacular daylight object, this particular scene in the world of optics proved of far greater magnitude than was perhaps apparent at the time.

Our cast comprises astronomers James Gregory (1638–75) and Isaac Newton (1642–1727), accompanied by optical instrument makers Richard Reeve (active 1640–80) and John Cox (active in the 1600s). Directing our players is diarist Samuel Pepys (1633–1703), whose writings give us so many precious insights into the world of science and astronomy from that time, that without these historical gems our cast would have to resort to uncertain improvisation.

The scene centres around astronomer James Gregory’s 1663 work entitled Optica Promota, and the design within for a reflecting telescope. Turning a series of line drawings from a sheet of paper into an actual working prototype was far easier doodled than done, and its actual construction remained a distant light at the end of a tube.

Of the opticians Gregory sought to assist with his telescopic dream, two names figure prominently in the account given by Pepys: those of Richard Reeve, manufacturer of optical instruments, and John Cox, also of good standing and reputation in the field.

However, neither Reeve nor Cox were able