204 The North-West Lunar Limb. 



can then be moved quickly to any altitude, and again secured 

 by returning the nut and collar to their original place. The 

 vibration of these arrangements is considerably smaller than in 

 the far more expensive and less convenient patterns which Mr. 

 Berthon's invention must replace as it becomes known. For 

 special purposes, when portability is not required, we should 

 prefer the stand for an astronomical telescope, described by 

 him in our No. for Nov. 1863 ; but the present invention sur- 

 passes that, and every other contrivance we have seen, intended 

 to support a portable instrument, and it is capable of being 

 packed up in a very small compass when required to travel. 

 Telescopes of any size, from fifteen inches to three or four feet 

 in length, may be conveniently mounted on these stands, and 

 their performance will be much improved by the steadiness and 

 smoothness of motion obtained. 



THE NOETH-WEST LUNAE LIMB.— CLUSTEBS AND 

 NEBULAE.— OCCULTATIONS. 



BY THE EBV. T. W. WEBB, A.M., F.R.A.S. 



After a somewhat lengthened absence, it is time for us to 

 return to our exploration of the lunar scenery, under the guid- 

 ance, as usual, of MM. Beer and Madler ; and we shall proceed 

 to examine the region lying along and near the limbs of the 

 First or North- West Quadrant, between our last object, 

 Cleomecles and the North Pole. From Gleomedes then, No. 1 

 in our Index Map, we shall take a northerly course. And here 

 it should be distinctly explained, once for all, that in our lunar 

 journeys N. and S. are not to be understood as they would be 

 in a diagram of a constellation, with reference to the N. pole 

 of the sky as viewed from the earth, but as they would appear 

 to us if we were actually on the spot — that is, with reference 

 to the N. pole of the globe of the moon. 



The first object of any importance that we meet with in 

 this direction is Geminus (No. 2 in our map), a crater 54 miles 

 across, and bounded by a ring rising on its W. side to nearly 

 17,000 feet above the interior. It contains two low and excen- 

 tric hills. Little can be made out here in the full moon, except 

 a brilliant but small crater, Geminus C, on its W. side, the 

 landmark, under those circumstances, of the district. Beyond 

 this little cup, still further to the W., lies a crater not far 

 from half as large and fully as deep as Geminus, and of extreme 

 interior steepness. It was named Bernoulli, by Schroter, who, 

 in his earliest measurement, found an enormous depth of nearly 



