satisfied himself that the dip given by his instrument at the station occu- 
pied by Prof. Loomis, nea Philadelphia, was sensibly the same as that 
erly made, which probably represented more correctly the dip at Phila- 
delphia. The result of two series of observations near the observatory at 
the Girard College, (at a sufficient distance to be eyond sensible influ- 
ence from the magnetic instruments,) made with four different needles, 
was as follows :— e. : 
July 21, 1840. No. 1, 71° 51.7’. No. 2, 71° 51.7.) Mean of Lloyd, 
No. 1 and No. 3, 71° 55.8’, 
November 2, 1840. No. 1, 71° 51.2. No. 2, 71° 51.0". Mean of 
Lloyd, No. 1 and No. 8, 71274; 
Mean, 71° 53.3’. 
The needles, termed Lloyd No. 1 and No. 3, are used without rever- 
sing the poles ; and a correction has been applied “ih the mean of six- 
teen comparisons, with the ordinary needles, at different places: as, 
however, this correction is obtained through Nos. 1 and 2, the results 
merely add to the number of observations from which the mean is ob- 
tained. 3 
Prof. Bache remarked that his former result was thus confirmed. 
At Baltimore, the place of observation was in the second square, N. E. 
of the Washington Monument. The same needles were used. 
Aug. 27, 1840. No. 1, 71°31.7. No. 2, 71° 39.1. Mean of Lloyd, 
No. 1 and No. 3, 71° 32.4’; Mean, 71° 34.4’, differing from the results 
of both the former series. 
Prof. Bache stated, in continuation, that the geological formations at 
and near Baltimore, rendered it difficult to select an unexceptionable site 
Magnetic observations there, and was a sufficient explanation of the 
tved discrepancies, The results, which he had at present obtained, 
— about 10' from the mean of those of Professors Courtenay and 
mis, 
Dr. Patterson announced the death of Prof. Charles Bonnycastle, a 
Member of this society, (elected at the last meeting,) which took place on 
the 31st of October. 
Nov. 20.—Dr. Patterson, from the observatory committee, reported, 
that an ordinance had passed the city councils, authorizing the erection of 
§ astronomical observatory within Rittenhouse square. It was subse- 
ently resolved, that the terms of the ordinance be accepted by the so- 
“ety, and that the observatory committee be instructed to take the neces- 
“ary Measures under the powers given them, for carrying into effect the 
ts of the ordinance. 
