[ 688 ] 
M. 
Macro car pen. See Si taciturn. 
Magnetic variation obferved at Cork, p. 17?. See Needle, 
Magnetifm. A thin cylindrical tin tube fufceptible of a confiderable degree of, p. £43. 
Marbles continually forming in the earth, p. 47. Their confolidation, how effedled, 
ibidi 
Meteorology. Neceflity of multiplying inftruments to determine the various influences 
of the air, p. 501. Meteorological journal for 1778, kept at the houfe of the Royal 
Society, p. 29$. 1 Metfeoftflogical obfervations on the coaft of Labradore, p. 657. 
journal for 1778, kept at Briftol, p. 551. 
Mica. How known, p. 29, 
Micrometer. Irtiperfe&ions of thaT which depends on moveable parallel wires, p. 419. 
/The uncertainties In the ob&rvations made with a divided objeCt gla fs one, invefti- 
gated, and f&und'to depend on its principle, p. 420. Advantages of a new catop- 
tric one,. 42 1, Its conftrudlion and properties, p.422. Method of adjufting and 
ofing it, p.425. Defcription of a new one, fuited to the principle of refradlion, 
p. 428. Its fuperiority to the objeft-glafs micrometer, what it confifts in, p. 429; 
if lines. Account of foihe baronietfical'eiperiinents in the mines of the Hartz, p. 488. 
Barometrical obfervations in feveral of thefe mines, p. £02. 
Monet , Mr. Caufe of his error in fuppofing that the femitranfparent fpar contains 
fulphur, p. 15. 
Montmartre, See Plajier, 
Moon, Obfervations of a luminous annulus furrounding her difk in an eclipfe of the 
fun, p. 106. EfFett of her atmofphere, p. m. 
Miipc, Account of an infant mufician, p. 183. What a fupernatural difpofition to 
miifiein infancy confifts in, p, 185. Hiftory of William Crotch, the infant mufician, 
p. 187. Aftonifhing properties of his ear, p. 197. His excellencies, what they 
confifl: in, p. 196. His powers of tranfpofing, at two years and four months old, 
whatever he played, p. 199. Account of mufical prodigies more advanced in age, 
p. 201, 202, 204. Conjectures on what William Crotch may mature into, p. 204. 
Experiments propofed to be tried with him, ibid. Abfurdity of leaving him to 
himfelf, without further teaching, p.205. Evident that he would like the plainefl 
mufic belt, if different genera and divifions of the mufleal fcale were tried upon 
him, ibid. Not all children fufceptible of being taught mufic, at leaft not in the 
cradle, p. 206. Primitive powers in mufic fometimes become ftationary, the reafons 
for it alfigned, ibid. 
Mozart . His talents for mufic at eight years old, p. 204, 
Needle^ 
