Notice of recent Measures of the Ring of Saturn

Extract

This communication chiefly described the observations made by W. S. Jacob, Esq., of the Madras Observatory, during the last apparition of the planet, with a telescope having a six-inch object-glass, lately completed by Lerebours and Secretan.

Previous to its being sent to India, the object-glass had been tested at the Edinburgh Observatory; and its quality, which was then approved, had been more conspicuously brought out in the subsequent trial in a clearer climate.

Immediately after the receipt of the object-glass, in September 1852, Mr Jacob directed it to Saturn, then in the zenith, and immediately perceived the “transparency” of the dark ring which has since been discovered independently by Mr Lassel and others; and on very accurately adjusting the focus, he saw a fine division in the outer dark ring.