OBSERVATIONS OF LUNAR OBJECTS. 



299 



light) north and south on the floor ; they are parallel, and are separated by 

 a darker region of an intensity equal to the west part of the floor, which ex- 

 tends over about one third of the longest diameter." At 6.0 the record runs 

 thus : — " There is no doubt of the northern streak of sunlight existing on the 

 floor, and traces of the southern streak are becoming apparent. Not the 

 slightest appearance of the streak seen by Bianchini (see Eeport Brit. Assoc. 

 1871, p. 73) has been observed. G.20. The northern and southern streaks of 

 sunlight are both decided ; their western extremities lie upon the line of fault 

 from N.W. to S.E. The long shadow of the peak a is now seen ; it ahgns 

 with the north part of II E'/'^ and the rock i;, or rather the inlet between 

 them and the bases of the first group of mountains of the Alps west of Plato. 

 6-30. The light of the northern streak is the most intense, although both are 

 faint. 6.45. The southern streak of sunlight is greater in extent (width) 

 than the northern, perhaps nearly double. Although definition on the 

 moon's surface is generally good, there appears to be a want of defining 

 power witliin Plato. Occasionally I see something approaching to well- 

 defined shadows, but greatly inferior to what I usually see with this glass. 

 The streaks of sunhght do not come out with that intensity which I re- 

 member to have seen them on January 10, 1870. 7.10. Sunlight on Plato 

 increases in intensity, but the shadows are deficient in definition, and the 

 streaks terminate on the east at some distance from the border, indicating a 

 considerable dip of the floor, if, indeed, the sunlight be reflected from the true 

 floor. 7.15. In best moments I see the northern edge of the shadow of the 

 peak y. The general character of the reflected sunlight is faint. The north 

 edge of the shadow of y aligns with the south part of II E'''^ and the sum- 

 mits of the group of mountains west of Plato, the bases of which aligned with 

 the shadow of h and the north part of II E-l-^. The floor appears to be much 

 darker than the site of Newton to the south." 



On the same evening Mr. Elger observed and sketched Plato ; his drawing, 

 fig. 21, made at 7.30, aperture 4 inches, power 115, exhibits a feature which, 



Fig. 21. 



so far as I am aware, has not been observed before, viz. a number of streaks 

 parallel to the longest diameter of Plato, which Mr. Elger described as " very 



