TERKESTRIAL MAGNETISM. 



11 



No. of 

 needle. 



Epocli of 

 commencing 

 vibration, 

 hrs. min. sec. 



Duratioii 

 of 500 

 vibra- 

 tions. 



h2 



Calculated 

 duration 

 at 60°. 



Square of the 

 preceding. 



Horizon- 

 tal inten- 

 sity. 



Total in- 

 tensity : 

 hor. be- 

 ing 1000. 



Total inten- 

 sity : that at 

 Cincinnati 

 = 1000. 



160. Mount Prospect Station.— Lat. 40° 40' 13" N. Long. 74° 00' 43" W. May 5, 1846. 



72° 27' 33" 

 Var. 5 54 04 W. 



4 

 5 

 6 



12 23 02.8 P 

 12 52 59.2 

 1 24 01.6 



1177.2 

 1430.4 

 1422.8 



82.0 

 81.5 

 83.5 



1175.52 



1428.25 

 1419.92 



13818472704 



20398980625 



20159658064 



Mean 



891.83 

 891.52 

 896.43 

 893.26 



2963.85 



994.22 



161. Coles's Station, Staten Island.— Lat. 40° 31' 50" N. Long. 74° 16' 50" W. May 11, 

 1846. 



72° 36' 03" 

 Var. 5 37 36 W. 



4 

 5 

 6 



2 03 00.0 P 



3 16 01.2 



4 01 03.8 



1179.2 

 1430.8 

 1426.6 



54.5 

 53.5 

 52.0 



1179.62 

 1431.45 

 1427.60 



13915033444 



20490491025 



20380417600 



Mean 



885.64 

 887.54 

 886.72 

 886.63 



2965.1 



994.63 



162. Newark, N. J.— Lat. 40° 44' 49"? N. Long. 74° 10' 00"? W. May 16, 1846. 



72° 50' 30" 

 Var. 5 32 42W. 



4 

 5 

 6 



7 59 00.0 A 



8 29 £9.8 

 8 57 £9.6 



1189.2 

 1444.4 

 1440.4 



68.25 

 69.00 

 69.80 



1188.56 

 1443.49 

 1439.16 



14126748736 



20836633801 



20711815056 



Mean 



872.36 

 872.79 

 872.53 

 872.56 



2957.70 



992.17 



163. White Hill, N. J. (near Bordentown).— Lat. 40° 08' 17" N. Long. 74° 46' 47" W. May 

 20, 1846. 



72° 06' 14" 

 Var. 4 22 28 W. 



4 

 5 

 6 



11 04 01.2 A 

 11 38 02.8 

 6 18 02.0 P 



1158.8 

 1412.4 

 1407.6 



66.0 

 65.0 



S8.8 



1158.35 

 1411.91 

 1406.73 



13417747225 918.46 



19934898481:912.27 



19788892929 913 22 



Mean 914.65 



2976.5 



998.46 



REMARKS. 



160. Mount Prospect Station. — Geology: a hill of sand and gravel, which commences at this point 

 and extends interiorly into Long Island. The sand and gravel abound with small trappean and granitic 

 bowlders. 



161. Coles's Station, Staten Island. — Locality: the dip and intensity, by the Hansteenian needles, 

 were taken in a grove about one-third of a mile northwardly from the station. Geology : the drifted 

 materials of this neighborhood abounding with primitive and trappean gravel, and bowlders. The declina- 

 tion was taken precisely at the survey station, as indicated by latitude and longitude above. 



162. Newark, N. J. — Geology: alluvial soil, sand and gravel superimposed on the new red sandstone 

 in place. Had been some- rain and wind. 



163. White Hill, N. J. (near Bordentown). — At the station immediately on the bank of the Dela- 

 ware. Geology : the tertiary marls of New Jersey. 



