TRANSACTIONS OF THE SECTIONS. 55 



Madler, appropriated the term " Montes Hercynii," at the same time transferring 

 the name " Lichtenberg " to a crater some little distance from this plain. Dr. Lee 

 illustrated his description of the plain and irs surrounding mountains by copies of 

 foiu- delineations, which, with the one on Lohrmann's map, are all that are m exist- 

 ence—one by Schriitor, made in the year 1792 ; the portion of Beer and Miidler's 

 map of this legion ; a iino drawing: of the northern part of the plain by Lord llosse ; 

 and an unpublished drawing by Mr. Birt, executed during tlje present year. In 

 these drawings. Dr. Lee pointed out the features that were common to them, espe- 

 cially a large crater on the north part of the west wall, which was very conspicuous 

 in them all. The west wall Dr. Lee remarked is tlie most i-ateresting of the two 

 principal ones which bound the plain. This wall is shown by Schioter as being 

 perforated by fom craters, including the conspicuous one above mentioned. Of 

 these craters the author said Beer and Miidler have but one on their large map. 

 LordRosse's drawings of a part of the chain only have the nearest to the large crater, 

 and Mr. Birt appears to have observed the four given by Schrciter. After alluding 

 to the confusion likely to arise from the changes in the names before mentioned, 

 Dr. Lee suggested that in future this large plain should be denominated " Otto 

 Struve," as "commemorative of the extensive astronomical labours of the asti'ononier 

 of Pulkova ; and that the crater to which Beer and Madler gave the name " Lich- 

 tenberg" should still retain it, especially as, according to theGerman selenographers, 

 it is almost unir[uo in exhibiting on some occasions a red tint. 



Notice of the Physkal Aspect of the Sun. 

 By Professor Phillips, M.A., LL.D., F.E.S. 

 Since the author had been provided with the diagonal sim-glass adjusted to his 

 equatorial by Mr. Cooke, he had taken many occasions for scrutinizing the aspect 

 of the sun's disk in regard to spots, faeulre, and the general porosity of the surface. 

 For tracing the path of a spot across the disk, a Kellner eyepiece was employed, 

 with five engraved transit lines, the intervals being equal to 10° in the central 

 part of the sun's circumference. In drawing, negative eyepieces of the ordinary- 

 kind were sometimes employed ; at others, a pecidiar kind, arranged by himselt, 

 with powers varying from 75 to SOO, the best performances being usually between 

 100 and 200; the higher powers, however, being occasionally usefid towards the 

 limb of the sun. He described the bright streaks or faculte as of diversified form 

 and distinct outline, either entirely separate or coalescing in various ways into 

 ridges and network. When the spots became invisible near the limb, the undu- 

 lated shining ridges and folds still indicated their place, being more remarkable 

 thereabout than elsewhere on the limb, though almost everywhere traceable in 

 good observing weather. In a diagram made on the 29th of March last, faculae 

 are slfown in the most brilliant parts of the sun. They appear of all magnitudes, 

 from barely discernible, softly gleaming spots a thousand miles long, to continuous, 

 complicated, and heaped ridges 40,000 and more miles in length, and 1000 to 

 4000 miles and more broad. They are never regidarly arched, and never found 

 in straight bands, but always devious and minutely undulated, like clouds in the 

 evening^sky or very distant ranges of snowy mountains. When minutely studied, 

 the ridges appear prominent in cusps and depressed into hollows. By the frequent 

 meeting of the briglit ridges, spaces of the sim's siuface are included of various 

 magnitudes, and forms somewhat corresponding to the areas and forms of the 

 irregular spots with penumbraj. Ridges of this kind often embrace and enclose a 

 spot, though not very closelv, the spot appearing the more conspicuous from the 

 ■surrounding brightness ; but sometimes there appeara a broad white platform 

 round the spot, and from this the white crumpled ridges pass in various directions. 

 Towards the limb the ridges appear nearly parallel to it ; further off this cha- 

 racter is exchanged for indet«i-minate direction and lessened distinctness ; over the 

 rest of -the siuface they are less conspicuous, but can be traced as an iiTegular net- 

 work, more or less disg'uised by that structure which has been designated as porosity. 

 The faculaj preserve their shapes and position, with no visible change, during a 

 few hours of observation, and probably for much longer periods. They do not 

 appear to project beyond the general circular outline of the sun — a circumstanc-e 

 which the author explains, without denying that they actually do rise above the 



