182 OBSERVATIONS OF THE MAGNETIC DIP IN THE UNITED STATES. 
Date. Hour. PoLaRivy. No. READINGS. Dip. 
1842, Aug. 80. 10—11 A. M. Mark down. 40 72 =©46.9. 
Us a ee Mark up. 40 46.9. 
Gs £ ct Mean result. 80 46.9. 
1842, Sep. 14. 3—6 P. M: Mark down. 40 41.6. 
‘ “ “ Mark up. 40 46.5. 
“ 6 6 Mean result. 80 44.0. 
Mean of three sets of obser. 240 72 46.7. 
1848, June 26. 2—5 P. M. Mark up. 40 72 46.0. 
“ Gb ee Mark down. 40 48.4. 
ee ce iG Mean result. 80 Aree 
18438, Sep. 18. 73—93 A. M. Mark dowa. 40 72 «465.1. 
be a Gs Mark up. 40 50.5. 
ce ae WG Mean result. 80 47.7. 
1844, June 22. 7—8 A. M. Mark up. 40 UA STAD: 
a « aC Mark down. 40 51.8. 
is & bs Mean result. 80 49.7. 
1849, July 18. 3—5) Ne Mark down. 4() ODED: 
“ “ce G3 Mark up. 40 BBB. 
“ & ee Mean result. 80 55.4. 
1849, July 27. 7—9 A. M. Mark up. 40) (2 04ai6 
“ Ce ce Mark down. 40 56.2. 
“ & us Mean result. 80: 55.5. 
1849, July 27. 9—11 A. M. Mark down. 40 55.5. 
Gs “ a Mark up. 40 04.8. 
“ a “ Mean resu!t. 80 55.2. 
Mean of obser. in 1849. 260 72 ~ 50.4. 
1859, April 2. 103—12 A. M. Mark up. 40 72°” 65.6! 
ec “ Cs Mark down. 40, Q 58.9. 
«“ “ ee Mean result. 80 73 2:3: 
The following Table presents a summary of all the observations made at Hudson, Ohio, 
the numhers here given indicating the mean of all the observations of the year :— 
Date. Dirs. 
1838—68. 72° 48.2’. 
1839—46. 47.6. 
4840—35. 49.5. 
1841—60. 48.1. 
1842—52. 48.8. 
1848—59. 47.8. 
184447. 49.7. 
1849—56. 55.4. 
1859—25. §2.3. 
