348 OBSERVATIONS ON THE MAGNETIC DIP AND DECLINATION. 
No. of | Polarity of| Face of |Markedside|Mean solar time North end of Needle |South end of Needle] Mean of both ends | Attached Name 
Needle.|Marked end|[nstrument,| of Needle. |Of cbservation.) reads ____ feads _|__ofneedie, Thermometer. of 
of Needie, iH. M. Deg.| Mins.gTenths. |Deg |Mins.fT'enths.|/Deg.|Mins.gTenths.|( Fahrenheit.) |Observer, 
1 8 E E 10.28 4.m.| 70 . 52.5 70. 68 70 . b0.2 84° 
a bs " “= 10.34 70. 53 70°, 58 70. 55 
ds e & “ 10.36 70. 53.5 70.57 70 . 55.2 
ie - = = 10.38 70.54 70.58 70. 56 a 
ia - WwW WwW 10.45 Te Cae 72.04 72 «06.5 = 
= b A bg 10.46 72.10 72 . 02 72.06 zm 
Ae de 6 td 10.48 72.410 72.05 72 6 O10 88 o 
% « we % 10.50 a. LE 72. 04 72. 07.5 f 
65 bs WwW E 10.56 T1225 7) eer te 8} T1205 aA 
% = Me We 10.57 71. 24 ig hye 71. 20.5 my 
te % i de 10.58 71. 24 7, 71. 21,6 8 
«“ “ « «| 10.59 TA . 225 dP ih 71420 oy 
“ « E W / 11.05 71. 14 71.19 Tir. 1865 gs 
a = 7 11,06 71.14 14 5S 7 ere, 
seg ” - . 11.08 71.14 7s he eae 
% m san rs 11.09 71.14 ETS 71 415.7 
Neédle No. 1, gives, with marked end forth, 2 A OF 27 
With Marion ene SOU 6. 6 ay eo, ee et me WL’ Oa he 
Dip, by sixty-four observations on SB ee es te ee 
Four readings were taken of the needle in each position, in order to test the consistency 
of the several results. After each reading, the needle was raised from the agate sup- 
ports aud allowed to assume new points of rest upon the pivots. 
The weather was clear and the atmosphere dry, and a very light south-easterly wind 
perceptible. 
The above are the first observations ever made with this instrument. It arrived from 
Paris only a few weeks ago. Its two needles came unmagnetized, and were both mag- 
netized this morning, before commencing the observations. Observations on needle 
No. 2 were omitted this day, in consequence of the high degree of temperature, and the 
difficulty of procuring a proper shade for the instrument, as late in the day as noon. 
1841, June 4th_— Washington City, D.C. Near the centre of the public garden, east of 
the capitol, under an elm tree which is on the south margin of the northern middle 
avenue, or gravelled walk, running east and west. 
| 
are. See 4 scien Bisson) eoepic Oe evdils eli rete FN hte i a ja AAD sod Deed Saal | 
«“ en] «“ 7.30 71.21 126 71, 28 | J. D.G. 
és a7) ty WwW 71.46 71. 07 70. 69 71 08 68‘ |J.N.N. 
« «| 4 «“ ‘171. 06 70. 59 71. 02.7 J.D.G. 
« w 1 Ay E 8.00 71.39 71.34 71. 36.5 68.5 |J.N.N. 
« tegen) te «“ 71. 39.5 71.34 71. 36.7 J.D.G. 
“ é | f w | 8.07 "1. 34 71.39 71. 36.5 70. (\J.N.N, 
és “ “ “ 71 . 84 71. 39.5 41. 86.7 J.D.G. 
9 N E E 8.50 70. 51 | 70 . 56 10 . 53.5 73 (|J.N.N, 
i + poe as “ 70. 52 (70 . 55 70. 53.5 J.D.G. 
@ di Ww Ww 9.00 71.40 171.35 #14876 74 S.N.N. 
é i Reh ext ot. 41 71 . 36.5 Y1., 38.7 TD. Gs 
a eé Ww E 9.07 Vh .. O16 70. 56 70. 58.2 4.  LN.N, 
: éé ii ‘is 71. 02.5 70. 5Y 70. 59.2 J.D.G. 
- « E Ww 9,12 71. 82 "1. 87 71. 34.5 4. \J.N.N. 
ee “ “ “ 71.33 “1, 37 V1, 86 J.D.G. 
