ADDENDUM. lxvii 
122. The following are the final results for all the bars operated on* :— 
Makerstoun 3:65-inch collimator named M, unmarked, Ist series, 6 determinations, 0:00390 
3 gece eG SO eee de aes liom ey Givceth ae PO weries, 4. 0:00465 
BePATSDS 20 1, Nee, oe 2 Cn See PAs eget es .ood. Series: 4 0:00403 
Meats aa ois «SSR eral a Seca heen tbosasmimetesines qcnateMeasie es LUN SErIeS. 4 0:00397 
5th series, 6 0:00435 
Bence eee OREEEREPETE ee since se ncdeaes SOELOR OM Lou ae AL Mean of all determinations, 0:00417 
Prof. BACHE’S 3°65-inch collimator; named B, marked 4, series of 4 determinations, 0:00627 
Prof. FoRBgES’s 3°65-inch solid bar, named F, unmarked, ................. Neate see se 0:00569 
123. In the observations for the temperature coefficients, the water was con- 
tained in a small wooden vessel fixed upon the deflecting rod of the Makerstoun 
theodolite (unifilar, or nine-inch circle) magnetometer; the temperature was ob- 
tained from two thermometers with bulbs of different dimensions, one placed at each 
end of the immersed magnet, the mean of both indications being employed. The 
following table contains the results for 5 bars :— 
TasLe 14.—Observations for the Temperature Coefficients of different Magnets, 
September 8, 1847. 
THERMOMETERS. | Unifilar [Declination Bifilar Unifilar Temperature 
a Re oe Scale | Corrected, | Circle Reading | (oeticient, 
Reading. | Reading. an Reduced, BPS 
Se. Div. Sc. Div. 5 a ¢ Y 
182-42 6-30 236 54-79 
200-20 1-95 : 192 54-47 
193-65 1:55 : 48-03 
185-52 2-22 . 39-25 
192-47 2-55 ‘ 46-15 
204-85 2-60 . 58-80 
198-20 2-67 . 51-93 
190-10 3-02 : 43-40 
196-95 3-00 b 50:43 
207-05 3-25 , 60-63 
227-87 9-52 . 17-75 
221-00 9-77 : 10-53 
214-05 | 10-02 57 3-25 
220-25 9:97 . 9-63 
229-30 | 10-05 . 18-86 
222-97 | 10-22 “ 12.25 
215-00 | 10-45 : 3-93 
296-00 | 10-77 26-73 
304-15 | 11-22 34.79 | Onnoue8 
311-55. | 11-12 8. 49-45-61 Sitoree 
304-00 | 11-20 SS6GIBIE Racane 
297-50 | 11-67 27-67 
171-47 | 12-17 : 18-15 
195-75 | 12-25 : 42-99 
220-40 | 12-20 . 68-29 
336-00 | 11-87 : 66-99 
320-05 | 11-67 : 50-78 nantes 
303-90 | 11-62 . 34.26 
0-000088 
-000088 
-000089 
-000098 
-000090 
-000087 
-000098 
0.000094 
-000080 
-000083 
-000100 
-000095 
-000088 
0:000295 
-000316 
h. 
0 
1 
1 
1 
1 
2 
2 
2 
2 
2 
5 
5 
5 
5 
5 
5 
b) 
6 
6 
6 
6 
6 
6 
6 
6 
7 
7 
7 
* Each determination, it will be seen from Table 13, commences with the deflecting bar having 
the same end to the north ; this should have been avoided, since, in the event of increase of tempe- 
