144 Magnetic Observations at Cambridge, United States. 
BAROMETER. 
Date. A. B. é Cc. Y: D. é. M. 
1841. h, m. h, m. h. m. 
Oct. 26. | 30.128 | .029 4 43 021 ib 006 rag O01 
Nov. 1. | 29.712 | .007 3 54 022 11 28 004 4 19 —.009 
8. | 30.068 | .041 650 O10 ll 37 OL 5 40 —.006 
15. | 29519 | .009 Il 32 008 1 37 005 5. 16 
22, | 29.740 | .023 4 238 023, POLO -008 0 Oo —.001 
29, | 30.109 | .034 24 8 .012 ly 23 O17 6 13 —.007 
Dec. 7. | 29.846 | .009 15 24 014 2 16 003 0 25 —.004 
13. | 29.781 | .010 5 20 024 0 0.5 021 6 48 +.008 
20. | 30.207 | .029 16 14 008 0 28 013 7 36 
27. \ 30.039 | .036 3 24 017 Ogi -014 7 32 +.00025) 
1842, 
Jan. 3. | 29915 | .032 16 20 018 Lels 018} 7 15 + 004 
10. | 29.814 | .072 5 353 029 1 252 -021 6 54 —.00L 
17. | 29869 | .011 7 48 022 0 48 O13 5 54 —.009 
24, | 30.181 030 17 «(30 009 10 52 05 1 52 —.020 
31. | 29.834 | .036 3 14 O17 5 32 O11 6 14 
Feb. 7. | 29.926 | .029 22 48 OLD 11 10 004 0 —.011 
14, | 29.714 | .124 asi .037 2413 019 5. (9 —.015 
21. | 30.193 | .009 10 15 012 11 50 004 6 56 —.002 
The above are the co-efficients of the formula 
H=A-+B ain (t-+-4)+ C sin 2 (t+7)+D sin 3 (t+-) 
expressing the mean diurnal curve, during the week commencing with the annexed date ; t being the hour, counted from 
meun noon at Gottingen. 
M is the mean hourly change, independent of solar time, to be applied by the formula 
cE M (t—2h.). 
THERMOMETER. 
Date. A. B. B. Cc. y: D. 38. M. 
| 
1841. h. m. h. m. | h. m. | 
Oct. 26. 38.53 8.36 2 32 3.03 8 58 2 4 27 +18 | 
Nov. 1. 50.90 6.85 22 36 4.29 10 45 39 4 6 Si 
8. 33.12 4.06 | 23 3 164 7 57 J8 7 10 +.05 
15; 33.80 3.74 22 12 1.45 9 30 44 4 30 
22. 39.79 2.75 Ste 2a 1.74 Oe) 61 4 56 —.09 | 
29. 28.71 3.42 22 48 270 8 23 .92 4 12 
Dec. 7. 33.50 3.84 23 18 224 8 27 63 ANT +.26 
13. 38.90 3.16 21 41 09 7130 13 4 18 + 04 
20. 22.70 3.38 22 44 82 9 23 22 1 24 +.04 
27. 29.90 5.19 20 52 2.09 8 42 64 2 59 —.04 
1842. 
Jan:.. 3; 16.60 3.86 22 34 1.18 @ 50 22 3 36 +.04 
10. 34.20 4.50 18 41 3.12 8 1 1.04 A 02 | 
17. 36.97 8.01 BQ 1A 3.92 8 ll 1.20 3 39 
24, 20.25 6.96 22 29 3.01 7 44 | 1.07 (ed | 
3l. 43.70 4.39 2) Is 1.81 9 13 1.10 4 8 | 
Feb. 7. 28.70 5.96 21 48 294 7 48 -90 4460 | 
14. 35.80 5.50 19 48 3 21 9 gs 53 0 29 
21. 24.27 473 21 52 208 7 50 07 S¥D | 
The above are the co-efficients of the formula 
T=A-+B sin (t+8)+C sin2 (t+ y7)+D sin 3 (t4+3) 
expressing the mean diurnal curve for the week succeeding the annexed detes; t being the time, counted from mean 
noon at Gottingen. 
M is the mean hourly change, independent of solar time. It may be added to the formula, thus, 
=EM (t—2h.). 
