1835.] 



on the Height of the Barometer. 



255 



when it stood at 29*008, and reducing this to the level of 4 p. M., by subtracting 

 (•087), the average monthly difference between noon and 4 p. m., there is left 

 28-921 inches for the theoretical height of Barometer at that time. Noon 26th 

 is, of course, by Greenwich time, 25 days, 18 hours, nearly. 

 1834. August 7th, midnight, Perigee. 4 days, 18 hours, new moon. 



Barometer. 

 29-178 



•110 

 28-820 

 29-344 



•368 



lin. 



Moon's Dec 



. . 



22 q 40' N. 



2-20 



24 6 



4-10 



24 11 



0-70 



22 47 





19 55 . 



i»r 



2nd 



3rd 



4th, 



5th, 



The real maximum is on the 2nd, nearly at midnight, or 2 days, 13 hours, 

 Greenwich time. 



The Perigee is evidently out of the question. The comparison between the 

 time of conjunction, and that of moon's maximum declination, with the barome- 

 tric minimum, may be more clearly stated in a table, shewing the distance of each 

 of the former in days and quarters of days from the latter, thus : 



Distance of 



Time of moon's maximum declination 



Time of new moon. 



Days. 



Qrs. 



Days. 



Qrs.1 







2 



7 







3 







3 



3 



1 



2 



1 



1 



1 



3 



4 







1 



1 



2 











2 



1 



3 



From the 

 nearest ba- 

 rometric mi- 

 nimum. 



1823, Aug. 15th, 



1829, June 27th, 



1829, July 29th 12 1 1 >■ 



1830, May 26th, 



1833, May 21st, 



1834, Aug. 3rd 



Making the same allowance as is done in the case of the tides, viz. three days 



before, or three days after the event, for a coincidence ; all these instances of moon's 

 maximum declination may be considered as coincidences with their respective 

 barometric depressions : it is evident, that the times of conjunction cannot be so 

 considered. We must observe that the only instance of great separation between 

 the time of moon's maximum declination and the barometric depression, was in 

 1829, when the maximum declination of moon was at its least (not above 18° 20'), 

 and consequently only faintly felt. 



It now only remains for us to notice the minor barometric depressions, which 

 have occurred during the same period, and we will first take the minima of the 

 years which were above 29*200 inches. From the increase of rain, which occurs 

 when the moon gets within 10 degrees of the equator, we might have supposed 

 that the next lowest depressions would probably be found there — and this turns 

 out to be the case. I here subjoin the details. 



1827. 



June. 



28th,. 



29th,. 



30th,. 



July. 



1st, . 



Barometer. 



4 P. M. 



29-314 

 •222 

 •207 



•390 



Rain. 



Inches. 



4-40 

 3-72 



0-38 



Moon's 

 Declination. 

 9 40 N. 

 5 '.5 



1 31 N. 



2 51 S. 



Nearest new moon, June, 23 days, 22 hours; say 24 days, or 7 days' distance 

 from the depression. 

 1832. 

 October. 



5th, 



6th 



7th 



8th 



9th, 



Barometer. 



Rain. 



Moon's 



4 P. M. 



Inches. 



Declination. 



29-763 



# . 



15 51 S. 



•688 



1-71 



12. 31 



•201 



3-54 



8 34 



•696 



1-65 



4 11 S. 



•697 



. , 



28 N. 



