COMPASS IN IRON ARMOUR-PLATED, IRON, AND COMPOSITE SHIPS. 627 
Table I.—Values of the Constant Parameters P and c, Q and f at Standard 
Compass Positions in Her Majesty’s Ships. 
Geographical 
position. 
Date of 
observation. 
Original 
P. 
Corrected 
P. 
c 
^tan 9 
in England. 
C. 
Original 
Q. 
Corrected 
Q. 
/ tan 0 
in England. 
/• 
Armou 
1 
r-plated ships. 
Bellerophon.- 
-Bunt S. 51 
E. Distance of standard from stei 
•n 61 feet, 
from iron mast 15 feet. 
Spithead . . . 
3 xi. 73 
+ •024 
-•004 
0 
0 
+ •215 
+ •025 
-•012 d 
-•005 
Halifax, N.S. 
5 viii. 74 
+ •031 
-•002 
—0° 42'/ 
Quebec.... 
16 ix. 74 
-•002 
-•003 
Trinidad . . . 
1 iii. 76 
-•020 
-•003 
Halifax, N.S. 
21 vi. 76 
-•020 
-•010 
Quebec.... 
24 viii. 76 
-•020 
-•008 
Iron Dijke.— 
Built S. 39° 
W. Distance of standard from stern 81 feet, from iron 
mast \7\ feet. 
Plymouth. . . 
20 i. 71 
+ •407 
+ •158 + 
+ •060 
-•166 
16 ix. 71 
-•019 
+ 9° 5' J 
+ •048 
Gibraltar . . . 
x. 71 
-•047 
-•008 
6° N. 96° E. . . 
10 xii. 71 
-•047 
+ •097 
38° N. 136° E. . 
22 viii. 72 
-•no 
+ •010 
49° N. 140° E. . 
viii. 73 
-•099 
+ •028 
30° N. 133V B - • 
27 vii. 74 
— T23 
+ •054 
12f° N. 46° E. . 
11 iii. 75 
-•126 
-■016 
Plymouth. . 
27 vii. 75 
-•136 
+ •042 
Belfast.... 
5 ix. 76 
-•138 
+ •034 
Plymouth. 
18 vii. 78* 
+ •402* 
-•122+ 
—*108 
-•022+ 
Singapore. . . 
xi. 78 
-•193 
+ •031 
Yokohama . . 
vii. 79 
-•193 
-•021 
Hong Kong . . 
28- xii. 80 
-•208 
-•002 
31 xii. 81 
-•193 
-•037 
Triumph.—B uilt S. 45° W. 
Distance of standard from stern 105 feet, from iron mast 27^ feet. 
Spithead . . . 
15 v. 78 
-•033 
-•289 
+ -304 | 
+ •106 
-•020 
+ •044 
-•038 + 
-•013 
Equator, 241° W. 
20 vi. 78 
-•222 
+ 17°40'i 
-•012 
-2° 10'J 
23° S. 39° W.. . 
1 vii. 78 
-•214 
+ •009 
40V S. 781° W. . 
7 vii. 78 
-•194 
-•001 
Valparaiso. . . 
x. 78 
-•190 
-•007 
9p S. 80|° W. . 
7 ii. 79 
-•209 
-■001 
20° N. 157° W. . 
4 iv. 79 
-•195 
-•003 
SwiFTSURE.— Built S. 56° W. Distance of standard from stern 107 feet, from iron 
mast 28f feet. 
Plymouth . . . 
8 v. 82 
-•057 
-•233 
+ •304 j 
+ •110 
+ •010 
-•016 
+ •010 + 
+ •004 
1° S. 26° W. . . 
22 vi. 82 
-•182 
+ 17*40'/ 
-•007 
0° 35' J 
23° S. 43° W. . 
5 vii. 82 
-•227 
-•086 
Monte Video . . 
23 vii. 82 
-•236 
-•031 
Sandy Point, Ma- 
gellan Straits . 
4 viii. 82 
-•239 
-■016 
* Previous to this date the ship had been under repair at Birkenhead, 
t After re-correction by a permanent magnet. 
