OF THE DIP AND TOTAL FORCE. 



17 



0.000 1 





(Noon) 

 12" 



13 



14 



15 



16 



17 



18 



19 



20 



21 



22 



23" 



+21 J™ 



January 



February 



March 



April 



May 



June 



July 



August 



Septembe 



October 



November 



December 



r 



—427 

 —370 

 —461 

 —438 

 —182 

 —129 

 —236 

 —175 

 —380 

 —468 

 -293 

 —493 



—171 

 —186 

 -315 

 —328 

 +109 

 +054 

 +092 

 +153 

 —015 

 —249 

 —183 

 —310 



—025 

 —005 

 —059 

 +036 

 +292 

 +309 

 + 311 

 +445 

 +168 

 —103 

 000 

 —164 



+158 

 +105 

 +123 

 +146 

 +292 

 + 346 

 +384 

 +482 

 +204 

 —030 

 +035 

 +018 



+194 

 —005 

 +014 

 +182 

 +292 

 +346 

 +421 

 +409 

 +204 

 —030 

 +072 

 +091 



+085 

 —005 

 —059 

 + 146 

 +256 

 +200 

 +275 

 +226 

 +058 

 —030 

 000 

 +091 



—025 

 —042 

 —096 

 000 

 +036 

 +017 

 +092 

 +007 

 —015 

 —030 

 +072 

 +055 



—025 

 —151 

 —059 

 000 

 —036 

 —019 

 —017 

 -029 

 —015 

 —030 

 +072 

 +038 



+011 

 —224 

 +014 

 —036 

 -109 

 —019 

 —090 

 —066 

 +058 

 —067 

 +035 

 —055 



—025 

 —078 

 +050 

 —073 

 —109 

 —056 

 -090 

 —029 

 —015 

 +006 

 + 035 

 —128 



—025 

 —005 

 +014 

 +036 

 —073 

 —092 

 —090 

 —029 

 + 058 

 +006 

 000 

 —128 



+012 

 —005 

 +050 

 +036 

 + 036 

 —092 

 —090 

 +007 

 + 058 

 +043 

 000 

 —091 





Year 



Summer . 

 Winter . 



—338 

 —257 

 —416 



—112 

 +011 

 —236 



+100 

 +262 

 —059 



+189 

 +309 

 +068 



+183 

 +309 

 +057 



+103 

 +192 

 +014 



+006 

 +025 

 —012 



—023 

 —019 

 —030 



—046 

 —044 

 —048 



—043 

 —063 

 —023 



—028 

 —030 

 —023 



—003 



—008 

 +004 





To render the preceding table uniform with the similar one of the vertical com- 

 ponent, the values at the odd hours will, hereafter, he dropped, their weight is less 

 than one-half of that of the even hours ; the small difference in the times (0.9'") will 

 be disregarded, and the values of the dip and total force, immediately deduced from 

 the horizontal and vertical components, wiU refer to an epoch 21.1" after the full 

 hour. 



For greater completeness. Table III, of Part VIII, is here inserted. 



Table III.— 



Regulab, Solar-Diurnal Variation of the Vertical Force between July, 1 





1841, and July, 1845. Values op — . 







0.000 1 



0" 



2 



4 



6 



8 



10 



Noon 



14 



16 



18 



20 



22" 



+20.6° 



January. 



—059 



+238 



+040 



—026 



—026 



+172 



+172 



+304 



—092 : —323 



—224 



—158 





February 



—198 



+033 



—132 



.—165 



+099 



+231 



+ 264 



+396 



+ 198 —264 



—330 



—132 





March . 



-178 



+086 



—046 



—112 



+086 



+119 



+251 



+317 



+020 



—178 



—145 



-211 





April 



—353 



—155 



—122 



—023 



+175 



+274 



+ 274 



+340 



+241 



—023 



—320 



—320 





May 



—412 



-346 



—214 



+049 



+247 



+280 



+ 346 



+445 



+313 



+ 016 



—313 



—412 





June 



—528 



—297 



—198 



—033 



+198 



+.396 



+ 594 



+ 462 



+363 



—066 



—429 



—462 





July 



—571 



—406 



—241 



+056 



+221 



+419 



+ 584 



+ 551 



+386 



—043 



—406 



—538 





August . 



—485 



—386 



—287 



—089 



+109 



+406 



+ 736 



+571 



+340 



—023 



—386 



—485 





September 



—469 



—304 



—271 



—205 



+092 



+323 



+521 



+521 



+356 



+026 



—271 



—337 





October . 



—099 



+066 



000 



—099 



+231 



+198 



+198 



+198 



—033 



—198 



—264 



—198 





November 



—043 



—043 



—142 



—109 



+086 



+122 



+2.54 



+221 



—010 



—076 



—109 



—109 





December 



—059 



+139 



+040 



—059 



+040 



+139 



+205 



+205 



—092 



—290 



—191 



—125 





Year 



—287 



—115 



—131 



—068 



+129 



+257 



+366 



+377 



+165 



—121 



—282 



—290 





Summer . 



—469 



—317 



—221 



—040 



+175 



+350 



+508 



+482 



+333 



—020 



—353 



—426 





Winter . 



—106 



+086 



—040 



—096 



+082 



+162 



+224 



+ 274 



000 —221 



1 



—211 



—155 





Solar-Diurnal Variation of the Inclination. — The combination of the component 

 values of and to form the corresponding values of the dip is effected by the 



A0 = sin 6 cos e {^— ^) 



formula ^^ ...- „ ^-- „ . 



\ Y ^ 



A9 wiU be expressed in minutes. 0= 71° 59'. A + sign indicates an augmenta- 

 tion of the north dip ; a — sign the converse. 



3 December, 1884. 



