42 A. D. Bache on Declinometer Observations. 
ratios are nearly invariable from 10 a.m. to 6 P.M, and again — 
from 8 P.M. to 8 A.M. The easterly maximum and westerly 
minimum at 8 Pp. M. form again a marked feature. ; 
law governing the disturbances during a solar day is 
clearly shown, and is of a systematic character. The diurnal 
maximum distance of a from the regular curve in the 
diagram (D). The disturbance variation has but one maximum 
nd one m m. ts most prominent feature is the easterly 
deflection at 8 o'clock (+194) p. at. (at Toronto it is at 9 P. M)} 
the maxiroum deflection amounts at that hour to 32” of are, and 
to 45” at Toronto. The greatest westerly deflection occurs ab 
magnet to the west, and during the remaining hours (principally 
the short and partly interrupted series of observations ; 
_ itis my intention to continue the discussion of the observa 
tions made at the Girard College Observatory. ; 
After the above, was written No. 1185 of the Astronomische 
Nachrichten came to hand, containing Prof. R. Wolf’s interest- | 
ing results on.the close connection of the variation in the fre- | 
quency of the solar spots, and the corresponding inequality in 
the amplitude of the diurnal variation of the declination. He 
deduces for Munich the simple formula, @=6'-273+0'-0514, 
© @ represents a relative number expressive of the fre- 
quency of the solar spots, directly derived from observation, — 
and @ the amplitude of the diurnal variation. He found a close © 
