ON MAPPING THE SURFACE OF THE MOON. 7 



peak of that momitain-ridge) is denoted by 16 in Lohrmann's Sect. III., but 

 is called y by Madlee. For the first time did I miss Linuc, or rather its 

 crater-form, which at that time ought to have sho-svn with especial distinct- 

 ness and deeply shadowed. 



Schmidt obserTcd Linuc as a spot of light onhj, more or less similar to y 

 Posidonius, on the undermentioned days: 1860, Oct. IS ; Nov. 14, 17, 19, 

 22, 23, 24, and 2-5. On Nov. 26 ho recorded " no trace of Linne."' He also 

 observed it as alight-spot on Dee. 14-16 (and following evenings), 2.5, and 27. 

 On Dec. 27 he speaks of it as "inconsiderable." 1S67, Jan. 13, 14 to 19, 

 and 24, he still observed it as a light-spot or small white cloud. A\?,o on 

 May 23, he estimated it at 0-6 of Sulpicius Gallus ; May 24, estimated at 0-25 

 of S. Galliis ; June 22, 0-33 of S. Gallus ; and July 9, as the usual spot of 

 light. 



M. Flammarion observed the white spot on May 10, 1867, and described 

 it as under (Comptes Eendus, tom. Ixiv. 20 Mai, 1867, ISTo. 20, p. 1020.) 

 He does not appear to have seen either the large shallow crater, or the small 

 crater or hUl which were observed on the same day by Eespighi and Schmidt. 



" Une observation attentif montre immediatement que Linne n'est plus un 

 cratere. Aucuue ombre exterieure a I'est, aucune ombre au centre. En sa 

 place il n'y a plus maintenant qu'une nuee blanche circulaire, ou plutot une 

 tache blanche attenant au sol, laquelle, loin de s'elever comme un cratere 

 sur le fond un pen verdati-e de la mer de la Serenite parait n'etre ni en relief 

 ni en creux et ressemble a un lac plus claire que la plaine avoisinante." 



Trmislntwn. — An attentive observation shows immediately that Liane is 

 no longer a crater. No exterior shadow to the east, no shadow at the centre. 

 In its place there is now nothing more than a white circular cloud, or rather 

 a white spot contiguous to the ground, which, so far from elevating itself as a 

 crater on the slightly greenish ground of the Mare Serenitatis, appears neither 

 to be in rehef nor as a depression, but resembles a lalce brighter than the 

 neighbouring plain. 



1867, July 9. Mr. Huoorys measured the length and breadth of the white 

 spot, \\z. 7"'S54 length, and 6""138 breadth. On the same evening I measured 

 the white spot in the direction of position angle 0°, and found the diameter 

 in this direction 7'''004 ; the mean of the length and breadth gives 6"'996 

 for an intermediate diameter. 



1867, Aiigust, 6'' 8'\ Distance of meridian of Linne from meridian crossed 

 hy terminator at the moon's equator 0° 6'-4, Linne being unenlightened. 

 Later, when the moon was low in the west, Mr. Buckingham saw an oval spot 

 rise gradually out of the dark part of the moon, which projected a shadow to 

 the edge. 



From the sketch accompanying the note, it would appear that this spot 

 was somewhat elevated above the general surface, as the shadow extended to 

 the terminator, also the cone of the little crater is shown casting an exterior 

 shadow, the orifice being a black spot. On the same evening, at 8'' 30", Mr. 

 Bird noticed two notches on the terminator near the neighbourhood of Linne, 



1867, Oct. 5. Mr. Slack, of Camden Square (telescope 6|-inch aperture, 

 silvered glass reflector), observed the white spot. He says, " The next 

 night (Oct. 5) I thought the white patch round Linne smaller than on many 

 former occasions, but changes of this sort are very common." 



Mr. Webstee, of Dundee (telescope 7-inch aperture, achromatic object 

 glass by Cooke), records, " Oct. 5, I could see Linne only as a small faint 

 nebulosity." 



1867, Oct. 10. Mr. Slack. " The white spot Linne did not melt off gra- 



