132 



NOTES AND QUERIES. 



[2«<i S. X. Aug. 18. '60. 



The declination, or, as it is oftener termed, the 

 variation of the magnetic needle is, in this country, 

 Trest, not east, of true geographical north. " Some 

 years ago," as Clammild says truly, " its declina- 

 tion was eastward of north ; " but there is no re- 

 cord of its having been 22.° The earliest reliable 

 record dates from 1576, when J;he observed de- 

 clination in the meridian of London (Gi*eenwich ?) 

 was 11° 15' east of north. In 1580 it attained its 

 maximum rate in that direction, namely, 11° 17'; 

 and then, returning westward, from 1657 to 1662, 

 the needle pointed due north. In 1720 it had 

 attained a westerly declination equal to 13° 0', 

 and, continuing its course for nearly 100 years, 

 it attained the maximum of westerly declination 

 in 1815, which was 27° 18.' It then began to 

 return. In five years (1820) it was at 24° 11' 7" 

 west, and in 1850 22° 30'. I have seen no record 

 more recent than that of 1850. It is probable 

 the (west) declination is now 22" 5'. 



So much as respects the rates of magnetic de- 

 clination. Now for a few words about the vanes. 

 These apply only to such as profess to indicate 

 the directions of the four cardinal points— N., S., 

 E., W. No doubt many of them are wrong ; but 

 not in the sense, nor for the reason, which Clam- 

 mild suggests. The magnetic declination has 

 nothing to do with the cardinal points, excepting 

 so far as it assists in determining their exact di- 

 rections. Geographical north is fixed and in- 

 variable. What is called magnetic north is the 

 most unsettled and variable of natural phenomena. 

 " True as the needle to the pole " is a pretty 

 poetical fiction, but not a philosophical fact. Not 

 only is the direction of the magnetic needle vari- 

 able as respects locality, pointing due north In 

 one part of the world, and westward and eastward 

 of north at other parts ; changing from year to 

 year, and through long series of years — but It Is 

 subject also to seasonal variations, day and night 

 variations, and storm variations Innumerable. 



That many vanes, ancient as well as modern, 

 are greatly at fault, Is no newly-formed opinion of 

 mine. I believe any careful observer might easily 

 satisfy himself that there Is a variation In the car- 

 dinal points of these public directors, as well as 

 in the magnetic needle. What is popularly called 

 true north at one part of a town will be found to 

 vary 10° or 20° from true (!) north at another 

 part of the same town. How are such errors to 

 be accounted for ? Through the obstinacy or the 

 ignorance of the persons who were employed to 

 fix the vanes, who confounded magnetic north 

 with geometrical north, or perhaps did not know 

 the difference, or would not be Instructed by those 

 who did know. J. O. N. R. 



This varies In different places, where also Its rate 

 of deviation varies. In London the magnetic 

 needle pointed to the true north In 1657, and at 



Paris In 1669. (Humboldt, Cosmos, I. 175.) It 

 attained Its maximum variation westward In Lon- 

 don in 1815, reaching 24° 27' 28", and at Paris in 

 1814, reaching 22° 54'; at the rate of 8' 52" an- 

 nually In London, and of 8' 6" at Paris. The 

 greatest variation on record is at the Cape of 

 Good Hope, where in 1813 it reached westward 

 of the true north 28°, its mean annual movement 

 being 7' 55". At Berlin, Encke found that in 

 fifteen years (1839 to 1854) the magnetic decli- 

 nation had diminished 1° 49|' ; the variation has 

 therefore been at the rate of 7^ per annum, but 

 It has been a little greater In the second half of 

 the term than the first. The declination at Berlin 

 in 1854 was 14° 56' 52". (Year Booh of Facts, 

 1859, p. 104.) At London, In 1859, the amount 

 of declination was, according to the Photographic 

 Almanac, 21° 30' west. If this be correct, the re- 

 trograde movement has been at the rate of 4' only 

 per annum. Tlie points on the earth's surface 

 where the variation is the same are shown in the 

 Penny Cyclopa:dia (" Terrestrial Magnetism," 

 p. 237.). As the vanes for exhibiting the direc- 

 tion of the wind In this and other countries point 

 to the true north, the magnetic declination does 

 not affect them. But the variation of this decli- 

 nation in the same place makes it necessary to 

 reconstruct from time to time the Isogonal lines 

 of the magnetic charts. T. J. Buckton. 



Lichfield. 



JAMES AINSLIE. 



(2"« S. Ix. 142. 355.) 



Under this head I enclose some further notes. 

 The first are from a " MS. Index to Charters," 

 In the Register House, Edinburgh ; the Index 

 being the property of the Writers to the Signet, 

 and preserved in their Library : — 



Ainslie burgen de Jedburgh. — Carta Con Davidi et 

 Jacobo Ainislie suo filio de duobus hortis ex parte aus- 

 trali vici Vicecanonicorum Burgi de Jedburgb, Roxburgh. 

 24 Martii 1585. 



Ainslie Mercatori Burgen de Edin. — Carta Con Jacobo 

 terrarum de Derniok, Brigend, &-<j. Roxburgh, 26 Nov. 

 1607. 



Ainslie advocato. — Carta Magistro Cornelio terrarum 

 de Cowthroppill in Baroniain de Dolphingstoun unit 

 Haddington and Edinburgh. 18 Junii 1636. 



Ainslie. — Carta Con Magistro Conielio annorum redi- 

 tuum inibi content. 



The second charter on this list is evidently that 

 by which the Individual in question was entered 

 on the lands mentioned, p. 142. The last has no 

 date given, but as the next date that occurs Is 

 1647, it may be supposed to be a year or two 

 prior. 



Reference to the published Retours will furnish 

 a considerable amount of information additional 

 to that given at page 355., both with regard to 

 James Ainslie and the other members of his 



