TRANSACTIONS OF THE SECTIONS. 31 



The drawing accompanying this communication exhibits such reflective powers 

 and different shades of tint, as well as certain remarkable phenomena connected 

 therewith, which appear to be entirely unconnected with hypsometric relations, and 

 manifest only the ground markings of this part of the lunar surface. It (the draw- 

 ing) has resulted from the personal observations of the author, in accordance with 

 the recommendations of the above-named Committee, and is perfectly unconnected 

 with any previous delineations of this part of the moon's surface, further than the 

 relative positions of the three principal craters, which have been taken from Beer and, 

 Madler's large map, the observations having been made with one of the Sheepshank's 

 telescopes, the property of the Royal Astronomical Society, each consisting of an 

 original sketch executed at the time of observation. They extend from April to July 

 of the present year. The features delineated may be seen during the period of the 

 lunation that elapses between ten and fourteen days of the moon's age. 



In the following description each feature will he separately noticed, preceded by 

 a Roman numeral. References : — Names and Roman characters to Beer and Madler's 

 map, Arabic numerals to features that appear to be new to the author, or, in other 

 words, that he has not met with a description of. 



I. Burckhardt. — The appearance usually presented by this crater under this illumi- 

 nation is that of an ellipse, the northern and southern margins being more strongly 

 illuminated than the eastern or western, which evidently results from the incidence 

 of the solar light. The crater is in reality (as determined from hypsometrical inequal- 

 ities brought out by morning and evening shadows) one that is superposed on an 

 older depression, the extremities of the older crater being well marked in the evening 

 illumination. No part of the ancient one is seen between ten and fourteen days of 

 the moon's age, only the brighter rim of the modern, with a central mark somewhat 

 more luminous than the floor. 



II. (c) A somewhat intensely bright circular spot near the south-western margin 

 of Geminus. It is a small crater very apparent in the morning illumination, but 

 almost disappearing under the evening. 



III. (1) A dark mark near (c). It is not in the nature of a shadow, the incident 

 light being opposed to that view. The author is disposed to regard it as a portion 

 of the surface reflecting much less light than the crater. 



IV. (2) A bright narrow stripe emanating from (c) directed towards Burckhardt : 

 this stripe may be slightly too wide in the drawing. 



Note. — There is an extremely brilliant crater inCleomedes(A) in Beer and Madler's 

 map, with a similar stripe towards Burckhardt. 



V. (3) A bright stripe from (2) towards the dark ribbon (15) : this stripe extends 

 considerably beyond the dark ribbon towards the east. 



VI. (4) An extensive space of nearly the same uniform tint ; it is rather darker be- 

 tween Burckhardt and Bernoulli, and covers the southern part of Geminus. 



VII. Bernoulli. — The floor of this crater under the mid-day illumination is dark, 

 with a light rim seen under the same circumstances as the rim of Burckhardt. 



VIII. (a) A small but well-marked crater between Bernoulli and Messala. 



IX. (5) A curved bright stripe somewhat hooked, extending from (a) to Ber- 

 noulli. 



X. (6) A dark space somewhat lighter than the floor of Bernoulli, extending 

 between Bernoulli and Messala. It is not of the form shown in the drawing, a small 

 portion extending further west. 



XI. (B) A crater on the margin of Messala; it is not distinctly discernible under 

 this illumination. 



XII. (7) A bright space covering the northern part of Geminus, extending and 

 converging to (B), the crater in the southern margin of Messala. 



XIII. (8) A bright narrow stripe crossing Geminus ; it passes through the dark 

 ribbon, as may be seen with a powerful instrument, and extends towards the north 

 of Cleoniedes across the narrow stripe (3). 



XIV. (9) A bright narrow curved stripe, apparently the north-western margin of 

 Geminus. It is seen eastward of the dark ribbon, and extends towards the eastern 

 extremity of the stripe (3). 



XV. (10) A dark space somewhat like a spur, apparently within and external to 

 Gisminus, and dividing the curved stripe on its margin. 



