222 Dr. Herschel’s Observations of the Transit of Mercury 
and confused ; the outside of the tube of my telescope is quite 
dry. 
Northern Lights. 
(28.) Sept. 25, 1781. There are very strong northern lights ; 
their flashing does not seem to interfere with telescopic vision ; 
but all objects appear tremulous, and indifferently defined. 
(29.) Aug. 30, 1782. There are very bright northern lights, 
in broad arches, with white streaks ; yet I see perfectly well. 
(30. ) March 26, 1783. An Aurora Borealis is so bright, that 
37 Herculis, which it covers, can hardly be seen ; yet, in the tele- 
scope, and with a power of 460, 1 find no difference. I compared 
that star with y Coronas, which was in a bright part of the 
heavens, and in the telescope they appeared nearly alike. I 
suspected y\ Herculis to be somewhat more tinged with red than 
it should be; and examined it afterwards, when clear of the 
Aurora: it was indeed less red; but, as it had gained more 
altitude, the experiment was not decisive. 
Windy Weather. 
(31.) Jan. 8, 1783. It is very windy. The diameters of the 
stars are strangely increased, even those at 60 and 70° of alti- 
tude. Every star seems to be a little planet. 
(32.) Jan. 9, 1783. Wind increases the apparent diameters 
of the stars. 
(33.) Sept. 20, 1783. The night has been very windy; and 
I do not remember ever to have seen so ill, with such a beautiful 
appearance of brilliant star-light. 
Fine in Appearance. 
(34.) May 28, 1781. The evening, though fine in appearance. 
