20 
REPORT— 1847. 
Observations were made at a station 1600 feet lower, which proved that tbedife- 
cnccs were due to height only. 
On the Diurtial Motion of a Magnet frtely suspended is the &«di* j 
Magnetic dip. Mg J. BnoUK. 
These results were obUdiied from the observations at General SirT.M.Bfu!*®' 
obsenator)', of the magnetic dccltnatlun and of the horizontal and verticil oap 
nrnts of magnetic force. The units of reduction were obtained by metbooi- 
acribed by Mr. Broun in the Edinburgh IVnnsactions. 
From the similarity of the mc-ans for the months of January anti Dkciuc. 
February anti November, &c., the projected means of each pair of nondu 
were exhibited. It would be difficult to describe the peculiarities of theseifc—^ 
without the aid of the projected figures ; it was shown, however, that Ibeii^ 
motion of the north end of the magnet ns projected on ihe plane at right 
the direction of dip, consisted of two or three loops in winter, these loois 
gradually urifoldod in the a|)ring and autumn months, and disappearing 
tner months. The amounts of motion or the perimeters of the figure 
constant for the six months from April to September. It was believed 
motions were exhibited for the first time. Dr. Laraunt of Munich had pp^ 
observations upon the assumption that the total intensity is constant, wbidiM**® 
i» not the case. 
The Tnotion of the magnet due to the varying hour-angle of the mooD 
shown. It was noiuted out th.at the greater part of the motion ocwrred 
time of the mooms passage of the inferior meridian, a fact which it is extrcimir 
ficult to connect with auy hypothesis having rcj'erence to temperature as a cu 
these motions. 
Jhecoursc. on the Magnetic Condition of Matter, delivered in il^ 
I'ridng evening, June 25, 1847. Bg M. Faraday, LLM.. 
The subject of Mr. Faraday's discourse was that condition which is 
magnet upon matter not onlinarily magnetic, i. e. not capable of assonwng 
netre Mndition of iron, llfis condition he has expressed by the word 
implying in some degree both its relation to and distinction from 
diUun. Both these are made plain by a simple fundamental action 
when matter is subjected to the action of a powerful magnetic pole; ”. 
«H* magnetic, as iron, it is attracted towards the pole; if it be 
the contrary, repellwl. The magnetic condition of iron is so marked tM J.. 
rautioM are requisite in making its property manifest; but the diamogu ^ 
tion of such a body ns water, wax or bismuth, is by comparison so weak 
wssT# at once powerful and delicate are required to make it and its P, ® 
i uc Him pleat nu thod is l« attach a jrieceaf the substance to be 
of a light horizontal lever, as a long splinter of deal wood, the lever iuelf 
a sua{>endcr consisting of two or more lengths of coarse silk about tw 
long, placed Bide by side, having wmal tension, and attached bv 
same apou on tivo pieces of card, the one above and the other below, 
prohiun has great strength and scarcely anv tomion. and therefore, .1 
or an electro-magnet is placed near the suhstance to be examined and at 
IV „ , i • . ./ —...o.v... ujjuu Mna niusiraiea oy c**''-'.’— ntiwi* 
v\mker« apparatus; for though it causes elongated bodies to iak« 
aon characteristic iioMtiims, yet similar positions are sometimes given ^ 
waBPr magnetic in its nature; and though the 
. , . *” “'f kwo cases arc easily dUtinguiahwl, when the miod is 
j a It IS ID the contrary and certain actions of offrochow with the one 
AM the other, that the fundamental distinction of all 
fmn, .1 rilustrated and proved. Mr. Faradav separated many 
causctl bodies by effects of this kind, and showed 
«- u,when elongated, to assume u {losition transverse to tie hwj 
