Observations and experiments made at Port Bowen in the years 1824-25, on the figure of the earth, on magnetism, and atmospherical refraction / [Sir William Edward Parry].

  • William Edward Parry
Date:
1826
Catalogue details

Licence: Public Domain Mark

Credit: Observations and experiments made at Port Bowen in the years 1824-25, on the figure of the earth, on magnetism, and atmospherical refraction / [Sir William Edward Parry]. Source: Wellcome Collection.

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    Table V. Observations for determining the Apparent Altitude of a Aquilee at setting, by Captain Parry’s lower telescope. The corresponding observations for Refractions are contained in Table VI. Day. Time. 1 No. of Obser- vations. Mean Reading of the 4 Verniers. Correction for Apparent Altitude. Barom. Corr. to Temp. 4- 50°. Tera. Full'. Winds True. Weather. Remarks. Index. Level. 1825- Feb.16th 18th 22d h. h. 1 to 2 P. M. 2 to 3 P. M. 8 to 9 A.M. z\ to 4 P.M. 8 to 9 A.M. A Difference of t] 8 8 8 8 8 /lean a Di le two 32°2 48 33,75 285 37 12,5 322 48 OO 285 35 12,5 322 48 12,5 titude by repe cto for upp telescopes by // + IO * + 2»5 * + 10 ating c er tele zenith '/ — 10,25 — 16,25 + 29,25 -Pl'24,25 — 12,25 .ircle .... scope.... distances Of // 4 38 55>gl 57**9 56,03 55*4* 58,72 4 38 56»63 4 32 32>34 6' 2 4, 2 9 Inches. 29,831 29,831 29,608 29,645 29,791 SeeTa O -36 -345 f29 r 263 |-3° b. III. Easterly Easterly Easterly Easterly ESE Fine Clear Ditto Ditto Q had been on the board just before the observation. O not up. © had set. O not on the board. Observations by the micrometer, to obtain the angular distance between the two telescopes used for observing the setting of » Aquilae. The telescope placed on the board as before described. March 12th, 1825. From ioh 30™ to 1 ih 3om A. M. From Noon till ih om P. M. Upper wire1 Lower wire Upper wire Lower wire fixed. moved. fixed. moved. 6l,2 45*8 32 43 58,8 50,6 32»5 44 59*2 53 31*5 43*2 60, z 46*3 33*2 43*8 60,9 48,8 32>3 48 62,3 5* 33*8 43 60 49 32,8 43*8 62 49*4 36,8 45 61 49*3 36,2 47 63 49*3 37 47*5 60,86 49>25 33.8i 44*83 49.2 5 33*8i 11,61 + 8 turns of the screw =: 811,61 divisions. ______ 811,02 = -f 8 turns 11,02 Mean 811,31 x 47' 7 (the value of each . division) rz 6' 2j,og. Difference of altitude between the two telescopes by the repeating circle 6'24,29 by the micrometer 6 27 ,09 Mean 6 25 ,69 Altitude observed for the upper telescope (Table III.) 4 32 32 ,34