194. W. A. Norton on the Variations of the Declination 
TABLE I. 
peers hn 7 Mean (West) Declination at Toronto at every Observation Hour in every 
th of the year 1846, derived from three years of hourly Observations. 
Toronto Time. | . | | 
Astronomical| Jan. | Feb. |March|ApriJ.| May. |June. | July. | Aug. | Sept.| Oct. | Nov. | Dec, 
Reckoning. | | | 
er ee ee a ee a Ra te; 
He M. ‘ , ’ 7 ’ i i ’ 4 i 
12 3 = |80°31/30°63/30-07/30°21 30°25 /30 : 12 §/28°9 
13. 3 30°33/30-76|/30°17 29°85 31 3) Vvt 2700} 0U 74 30°03] 29°72 2 31-08 29:2 
14 3 ./29°64/30 65/29 99/30°67/31-48/31°10/30°60} 30°75 130 06/29°17 30°95} 29°7 
15 3 © |29°74/30-00 30-05/30°07/30°78)31-27 6429-60 30°14)292 
16 3 28°98 '30°20) 2994/2943) 36/30-49}30°46/28-75/29-05 30°30} 29°83 
Ve-3 29°62|29°28)29°77 "| 67/29:09!28-66}28'71 2991)29°5 
18 3 29°43) 29-26|/29°28/ 28- 13,267 %1}25-93/26:02126:36|29:53]29°37 2959)308 
19° 3 29°07|2 93) 8°63|27 1/25 68|25°13)24 54/24: 19 30° 20 29:56 29-21/30°14 
20 3 28°15/2 42/27°50/27°80 25°71 25°22) 24-48123-97}98-40}28-58 28-21} 28 96 
vay 3 28:33 29°47 vat ped | ou! ecy-0 7 so 98|26:20)29 58 28 28°36 28°53 
22 8 = {29°46/30°35/28-97/30°57/31-29/29°'38 28-96 2 29°78)28:'8$ 
28 3 |81°35)32°18/32°32/33°83/35:08/32°96/32°80|34°25 |35-00/32 i 2 31:87|30°37 
0 3  |38:19/33'80/34-95/36:49/37 01 |35°62/35°58/37'43/38-18]34-82 33:91/31°98 
1 3 |38°76|34-42/36°51/37-81/37-77/37°32|37-05 | 38 86| 3783/3773 37-48)/35°59 
+2 3 3°38/34°10/36-54/87-68)37-22 |37°30/87°15| 38°31 1374213518 3502 33°54 
8 3 = |32°76/33-21/35°84/36 91/85 96|36'49/36'43|36'44|35°45|34-02 3395/3272 
4 3 |31-60/32°38/34-49 9/35°17/34 13/35°12/35°15/34-48/33'33|33-23 33°34/31°99 
5 3 /80°82/31-98/83 832 17'33:23|32-70|31-41|32-57 82°52|3122 
6 3 30°48/31°3 3032 17/31°93/31-4 8 67 31:47 30°36 
7 3 /80:0(/30-94 31°32 3093 fF 31-40)31-11 31-43) 30-88|30°73|31° 33 2998|29°57 
8 3 28°81/29-93 30°7 S008 a9 pl ab 30°56 3071 43 3 12} 28°90 
9 8 28:92 29°53 29°60/50 08 30°34 31-08|28°30/30-40|29°61 2857/2877 
10. 3 29-57{29- 97/2 29°98/30°77/30:°59 30°31, 2129°52/29-70 29° 70 29 08)2831 
11 $8 29:56 30°16, 29°14 29°88 see a0 20-4 29 51/3062 /30°21 20°42 28:54 
i Means. |30°80 30°91, 31-19|31-54/31- 47131 16(30°92/ 31-04 |31°60/31 3106 31 “01/3022 
The corrections have been applied for the secular change, reducing to the mean 
epoak July 1st, 1846. 
autumn. The pr eae of the mean diurnal variation in the 
opposite seasons of summer and winter, are exhibited in the fol- 
pens © curves.  ( hee 3 and 4. 
s the difference in the amount of the daily range it may 
be ad ‘thas the diminution of declination in the morning hours 
is much greater in summer than in winter, and is comprised 
within a shorter interval of time; also that the turning point, 
from the easterly to the westerly motion occurs earlier in cpp 
than in winter. The greater diurnal range in summer 1s 4 con- 
sequence of the relative depression of the morning ee 
and elevation of the afternoon maximum. (See also Table I.) 
The depression is greater than the elevation. The morning 
minimum is 3°40 lower in June than in December, while the af- 
‘ternoon maximum is 1-74 higher in June than in December. At 
ahe hour of noon the declination is 3/-64 greater in June than in 
December. 
It will bag xf. be seen that the needle ought to Sot farther to 
‘thi n the morning hours in summer than in winter, when. 
We oeec:, that the points of deecimina esctibas t these hours 
