Obase.} 528 [July 19, 
the source of important meteorological perturbations. I shall not be sur- 
prised if the Barbados records, when I receive them, furnish data for 
settling the question definitely in the affirmative. Ican think of no more 
probable reason for the opposition between the Joviam curves at San 
Francisco and Lisbon, than the opposite directions of the ocean currents 
near the two coasts. 
The local disturbances are evidently greater at Sam Francisco than at 
Lisbon, but in spite of them all the two sets of lunar curves at the former 
station, (¢, 4), each set covering three entirely distinct and independent 
periods, exhibit striking points of similarity, and their differences are no 
greater than might have. reasonably been anticipated, in view of the 
variations in the solar curves (a). The same may be said of the 
monthly curves of heavy rainfall (0) and of frequency of rain (x) in dif- 
ferent periods. ' 
Interesting special resemblances at different stations are shown at 
Greenwich and Philadelphia, in Fig. 4, ante. vol. x., p. 585; at Philadel- 
phia, Lisbon and San Francisco, in all the lunar curves on p. 182 and in 
the average annual rainfall at Philadelphia on p. 181 (Table IV.) of the 
present volume, as well as in the accompanying curve which depicts the 
frequency of rain at San Franeisco from 1849 to 1857 (2) continuous line, )* 
The maxima in my Philadelphia annual curve are, somewhat more 
strongly marked than those in Schott’s diagram (Pl. III., Tables and re- 
sults of the precipitation §c., in the U. S.), on account of the different 
methods employed in computing the ordinates. Schott’s were calculated 
from the monthly means (op. eit. p. 124), mine from means which cover 
only s; of a year, and therefore show the characteristic features of the 
curve more nrinutely, besides being better suited for comparison with 
the thirty ordinates of the lunar curve. My anticipations (Jour. of the 
Franklin Inst., Ixiii, 205) that the San Francisco ‘‘daily records may 
probably furnish materials for more minute and detailed profitable inves- 
tigation,’ having been thus satisfactorily realized, I now await the ar- 
rival of the Barbados records, with the expectation that their discussion 
will exhibit evidences of lunar, and possibly of planetary action, analo- 
gous to those which I have found at other stations, but still more promi- 
nent and more decisive than any that have ever hitherto been published. 
If there are any observations, extending over a long series of years, mear 
the Gulf of Fonseca or on the Southwestern coast of Peru, I think they 
will furnish indications of the special importance of the lunar aetion on 
the barometric pressure, similar to those which I have found at Philadel- 
phia, but that such indications will be more marked on the Peruvian 
coast, than on either coast of North America. 
*Indieations of a general maximum near full moon, with a diminution at the precise time of 
solar opposition, are to be found im the majority of the curves which I have computed. 
They afford, as I think, further confirmation of my third prediction. The surface tidal eur- 
rents have their greatest Eastward velocity, and the upper atmosphere has its greatest 
Westward lagging, when the sun is onthe upper andthe moon on the lower meridian, The 
blending of currents is therefore peculiarly favorable for the precipitation of moisture, but the 
intense meridian heat appears to partially counteract the precipitation by re-ewaporation. 
