MAY 
Weidler, In his lviftory of aftronomy. While Mayer was 
bufily employed in examining more accurately the motion 
of each fatellite, Galileo publifhed his Nuncius Syderius, 
in which he claimed the fame difcovery, having feen thefe 
fatellites in January 1610. At length Mayer, after he had 
completed his obfervations, and conftruffed tables of the 
longitude and latitude of the fatellites at all periods, gave 
a complete account of his di Cep very in a work eniitled 
“ Mundus Jovialis, anno 1609 deteffus, ope perfpicilli 
Belgici; hoc elt, quatuor Jovialum planetarum cum theo- 
ria, turn Tabula; propriis obfervationibus maxima; fun- 
data;, quibus fitus illorum ad Jovum ad quodvis tempos 
datum promtiffime et facillirrte lupputari poteft Norim- 
bergae, 1614, 8vo. Mayer named the new ftars, in honour 
of his prince, Sidera Brandenburgica ; but he gave alfo a 
particular name to each. On the other hand, Galileo 
named them Mcdicean ; and in his Trutinator did not hsfi- 
tate to infer, becaufe Mayer had not given the periods of 
them correffly, that he had never feen them. But Caffini 
defends Mayer; and fays, that, when the methods which 
he employed are confidered, there can be no doubt that 
he oblerved them ; and Montucla is of the fame opinion. 
This aftronomer lays claim alio to the difcovery of the 
fpots in the fun, which he fays he faw on the 3d of 
Auguft, 1611. He publifhed alias' “ Tabulae direCtionum 
novae univerfae Europae infervientes,” 1599; and died, at 
Onolzbach, in 1624. Montucla, Hijl. des Mathematiques . 
MA'YER (John-Frederic), a learned German Lutheran 
divine, was born at Leipfic in the year 1650. With re- 
fpeft to the hi dory of his life, we have no other informa¬ 
tion, than that he became profoundly (killed in the Latin, 
Greek, and Hebrew, languages; was admitted to,the de¬ 
gree of doffor of divinity; filled the chair of profeffor 
iucceffively at Wittemberg, Hamburgh, and Stettin in 
Pomerania; and died in the year 1712, about the age of 
fixty-two, with a high character for erudition, of which 
his productions (how him not to have been unworthy. 
He was the author of, 1. Bibliotheca Biblica, 1702, 410. 
which treats of the mult celebrated Jewilli, Chriftian, Ca¬ 
tholic, Calvinift, and Lutheran, authors, who have em¬ 
ployed themfelves in illultrating the lacred feriptures. 
2. On the belt Method of ltudying the facred Scriptures, 
1694, 4to. 3. Hiitory of Martin Luther’s German Verfion 
of the Bible, with a fhort Account of the Tranllations of 
the facred Books before his Time, See. 1701, 4to. 4. Of 
the Modems, who have written againft the lacred Scrip¬ 
tures, 1707. 5. An Expofition of the two fir A Pfalms, 
1702, 4to. Belides a vait number of Enquiries, Dilferta- 
tions, controverfial Treatiles, &c. Morcri. 
MA'YER (Tooias), a very able German aftronomer 
and mechanic, was born at Marfpach, in the duchy of 
Wirtemberg, in the year 1723. His father was an inge¬ 
nious civil-engineer, who particularly excelled in hydrau¬ 
lics; and young Tobias, who was fond of obferving him 
while at work, dilplayed an early inquifitivenefs concern¬ 
ing fuch ingenious purfuits; and from the age of four 
years began to delign machines with the greatelt dexterity 
and exaftnefs. The death of his father, however, whom 
he loft when very young, probably prevented him from 
being educated to that employment. Poflcffing but fcanty 
means for obtaining afliftance in his ftudies, lie was obliged 
to rely on his own energies, by which he made himfelf a 
proficient in mathematical learning, and became qualified 
to be an able initruefor of others. While thus occupied, 
he alfo aftiduoully cultivated an acquaintance with claltical 
and polite literature, and learned to write the Latin tongue 
with elegance. So weil eftablillied was his reputation 
when he had attained to his eight -and-twentiei h year, that 
the univerfity of Gottingen nominated him to the chair 
of mathematical profelfor; and not long afterwards he 
was admitted a member of the royal focicty in that town. 
From this time, every year of his fhort but glorious life 
was diitinguilhed by loins confiderable difeoveries in geo¬ 
metry or altronomy. He invented, lcveral uieful initru- 
ments for the more commodious and exaft meafurement 
M A Y 575 
of angles on a plane. He correffed many errors in practi¬ 
cal geometry, tracing them to their origin, in the refrac¬ 
tions occafioned by terreftrial objects. Afterwards he 
particularly applied himfelf to ftudy the theory of the 
Moon, its appearances, the queftion of its atmofphere, 
and the reciprocal actions of the Sun, Earth, and Moon, 
upon each other. He then extended his obfervations to 
the planet Mars, and the fixed liars ; determining with 
greater exaiffnefs than before the places of the latter, and 
afeertaining that, though commonly denominated fixed, 
they po fiefs a certain degree of motion relative to their 
refpeffive fyftems. Towards the end of his life, the mag¬ 
netic needle engaged his attention, to which he affigned 
more certain laws than thofe before received. To thefe 
various enquiries and obfervations he applied with fuch 
indefatigable a (lid uity, that lie died exhaufted and worn 
out by his labours, in 1762, when only thirty-nine years 
of age. His Table of Refractions, deduced from his aitro- 
nomical obfervations, agrees very nicely with that of Dr. 
Bradley; and his Theory of the Moon, and Altronomical 
Tables and Precepts, were fo well received, that they were 
rewarded by the Englifh board of longitude with the pre¬ 
mium of three thoufand pounds, which fum was paid to 
his widow after his deceafe. Thefe Tables and Precepts 
were publifhed by the hoard, in the year 1770. The prin¬ 
cipal works which he gave himfelf to the public were, 
j. A new and general Method of refolving all geometri¬ 
cal Problems, by Means of geometrical Lines, 1741, 8vo. 
in German. 2. A Mathematical Atlas, in which all the 
Mathematical Sciences are comprifed in lixty Tables, 1748, 
folio, in German. 3. A Delcription of a Lunar Globe, 
conlfrufted by the Cofmographical Society of Nuremberg, 
from new Obfervations, 1750, 4to. alfo in German. Se¬ 
veral Maps; and fome valuable papers in the Memoirs of 
the Royal Society of Gottingen. The firft volume of his 
Works was publifhed at that place in 1775, in folio; but 
we do not know that the feries has been completed. Gen. 
Biog. 
MAYER'GA, a town of Spain, in the province of 
Leon : twenty-three miles fouth fouth-eaft of Leon. 
MAYER'NE (Sir Theodore Turquet de, Baron d’Au- 
bonne), an eminent phyfician, was born at Geneva in the 
year 1573. His father, Louis de Mayerne, author of A 
General Hiitory of Spain, and of Monarchic arijlo democrat 
tique, and a Calvinift, had removed thither the preceding 
year, on account of religious perfecutioil, from Lyons. 
Alter being inftrufted in the rudiments of literature in 
his native city, Theodore was lent to the univerfity of 
Heidelberg, where he remained fome years; after which, 
as he had made choice of the profelfion of medicine, he 
removed to Montpellier, where he received the degree of 
doctor in 1597. He then went to Paris, where he became 
acquainted with Riverius, firft phyfician to king Henry IV. 
through whole influence he was, in the year 1600, ap¬ 
pointed to attend the duke de Rohan, as phyfician, in his 
embafly to the diet at Spire ; and alfo nominated one of 
the phyficians in ordinary to the king. On his return, he 
availed himfelf of the privilege which the latter office af¬ 
forded him, and praefifed in the metropolis, where he alfo 
gave public lectures in anatomy and in pharmacy to the 
young furgeons and apothecaries. The latter of thefe 
iubjetts led him to treat of chemiffry, to the practice of 
which he had paid peculiar attention; and his recommen¬ 
dation of chemical remedies drew upon him a confiderable 
degree of enmity from the faculty of Paris, who mani- 
felted their attachment to Galen by an indiferiminate 
abule of all who ventured to employ any mode of treat¬ 
ment not mentioned in his works. Quercetanus was joined 
with Mayerne in this attack; and one of the faculty, in 
1603, publifhed a book againft thefe heterodox brethren, 
entitled “ Apologia pro Hippocratis et Galeni Medicina, 
contra Mayerniutn et Quercetanum.” To this Mayerne 
replied immediately in another “ Apologia, in qua videre 
elt, mviolatis Hippocratis et Galeni legious, Remeiiia che- 
mice praeparata tuto ulurpari polTe;” in which he made 
fome 
