204 Captain W. S. Jacob on the 



scrvations or discoveries do not seem to have gained much 

 attention or credit at the time, or to have been followed up in 

 any way, and the memory of them had almost died away, until 

 revived by their re-discovery in 1850, since which time they 

 have been verified by a host of vigilant observers, with powerful 

 instruments ; and some of them have recorded their experience 

 in the form of drawings or engravings, so as not only to give 

 the general public a pretty correct notion of what had been seen 

 with the best instruments, accessible only to few, but also to pre- 

 clude the possibility of the subject again sinking into oblivion. 

 The plate here given (Plate II.) represents the planet as 

 seen at Madras in the latter part of 1852, with the equatorial 

 instrument constructed by Messrs Lerebours and Secretan of 

 Paris, the object glass of which has an aperture of 6 \ inches, 

 and a focal length of 88*6 inches, and whose defining power 

 is of a high order. Other favourable circumstances were, 

 the planet's proximity to the zenith, and the tranquillity 

 and transparency of the atmosphere. The obscure ring 

 was well brought out the first time it was looked for, and 

 the fine line on the outer ring was also seen distinctly 

 enough to allow of good measures being made with the filar 

 micrometer, although, strange to say, its very existence is still 

 questioned in some quarters, as it is not visible in some of 

 the largest telescopes, such as the Poulkova Refractor; very 

 neat definition, rather than a great amount of light, being re- 

 quired for the purpose. The transparency of the obscure ring, 

 exemplified by the planet's limb appearing through it, would 

 seem to have been first noticed at Madras, being shown in a 

 drawing taken on 22d September 1852, and forwarded to a 

 friend in this country, in a letter dated 11th October. This 

 ring, as seen across the planet, has a light umber-brown tint, 

 and a filmy, smoky character ; the division between the two 

 principal rings (usually represented black) had nearly the 

 same tint, while its outer edge was not sharply defined, but 

 shaded off, as shown in the engraving. No separation, either 

 by a dark or bright line, could be discerned between the 

 bright and obscure rings ; on the contrary, the impression was 

 that the shading in the former was produced by the latter over- 

 lapping or enveloping its edge. 



