302 OBSERVATIONS ON THE MAGNETIC DIP, 
i rare . 
i The dip is here so unusual, that I shall use the observations made May 8, 1841, to fur- 
nish the unit for the following series. 
oo 53. Cincinnati, May 8, 1841. 
! (See series for 1841.) ee ce 1000, | 2986.38 1000. 
Logarithm,}1.4751456 
54. Pittsburgh, Latitude 40° 32’, N.; Longitude 80° 02’, W.; April 7, 1842. 
| | Duration jCalculated i} Total inte ty, 
Dip. | No.of |Epoch of commencing| of 500 | Tempe-| duration Square of the Horizontal/Total intensity, |that at Cincin- 
\Needle. Vibrations. hese decicadk as.sace at 60°. preceding. intensity.| Hor. being 1000, /nati being 1000. 
4h.39m.08.16 P}1634.4 | 74° 1631.70/2662444.89 890.29 
38 13 02 4 {1612.8 | 73 {1609.8 |2591456.04 (891.18 
5 47 03 2 /|1299.2 | 71 {1698.4 |1685842.56 
| Mean, |890,73 2998.64 1004.10 
72°43'12”") 
| 
wWd= 
Locality, as in previous series. 
55. Chambersburg, Pennsylvania, Latitude 39° 55’, N.; Longitude 77° 40’, W.; April 9, 1842. 
71°57'04") 1 1h.05m.03s.6 |1605.6 | 73°5/1602.1 |2566724.41 [923.49 
1 39 06 4 {1585.6 | 71 0/1583.1 |2506205.61 |921.49 
2 11 59 6 |1289.2 | 68 5/1288.6 |1660489.96 |919.82 
2 42 30 1156.4 | 67 0/1155.9 |1836104.81 (922.59 
5 3.10 02 8 /1407.6 | 65 0/1407.1 |1979930.41 |921.19 
6 3 438 02 8 {1404.0 | 64 0]1403.5 |1969812.25 {920.88 
Mean,'921.57 2975.52 996.36 
= CO 0 
Half a mile west and alittle south of the court house, and five hundred feet south of 
the stream, just on top of second bank, in a woodland. At two hours thirty minutes 
had become hazy, wind north-west, gentle. Substratum, dark-blue limestone, highly 
inclined. 
56. Mount St. Mary’s College, Emmetsburg, Latitude 39° 41’, N.; Longitude 77° 18', W.; April 12, 1842. 
71°46'20"| 1 | 8h.57m.028.8 A,1596.4 | 66° {1595.3 |2544982.09 (931.39 
i 4 05 02 4P/1574.8 | 72 [1572.0 /2471184.00 [934.55 
Pog j10 03 «04 Al1280.8 | 70 {1280. j1627920.81 |982.39 
9 09 O83 6 |1150.4 | 58 {1150.7 {13824110.49 /|930.95 
8 25 O1 2 {1399.6 | 64 8/1399.1 |1957480.81 |931.76 
6°17 OL 0% 1394.8 | 61 |1394.7 |1945208.09 932.52 
Mean of 5 needles,/931.90 2979.26 997.66 
On the left bank of a brook, which, descending the mountain, passes the college. 
Indurated or metamorphic sandstone. 
57. New Haven, Latitude 41° 18’, N.; Longitude 72° 56’, W.; April 21, 1842. 
73°29'47"| 4 | 1h.23m.03s.2 Al1211.2 |50° 1212.00|1468944., 1839.16 
iS 7 56 038 6 {1475.2 |52 5 |1476.00/2178576. 1837.20 
| 6 8 30 02 4 {1469.6 |55 7 1470.15 aieienl ere ca ee 
| | Mean,|838.54 2951.82 988.44 
At a locality called “ Highwood,” a part of the Hillhouse estate. Substratum, sand- 
stone; trappean rocks within a few miles. 
