MASK 
him, though at firft he received only the half. While 
pleading his caufe, he attacked the agronomical methods, 
availing himfelf of fome adiniffions of La Caille, who, 
with his incorruptible integrity, while boafling of the me¬ 
thod of the lunar diftances, admitted that they had 1'ome- 
times led him into error. Mafkelyne proved by his own 
obfervations that the errors are much diininilhed when 
better inftruments are employed than thofe ufed by La 
Caille, fuch as were then beginning to be conltrufted in 
London. It is poffible that, in this difpute between me¬ 
chanics anil aftromotny, both fides went a little too far. 
The time-pieces performed every thing demanded by the 
aft of parliament of 1714; and there can be no doubt 
that, if they had been prefented at that time, Harrifon 
would have obtained the whole reward without difficulty. 
But fifty years afterwards, when the inftruments were 
much more complete, when the lunar obfervations had 
received unexpected improvements, was it not excufable 
to demand a little more accuracy? The time-pieces, by 
the facility they offered, were likely to feduce mari¬ 
time men, who are ufually enemies to long calculations; 
but their exaftnefs, it was faid, could only be truffed in 
Ihort voyages ; and that in lefs ordinary circumftances, 
and in long navigations, the method of lunar diltances 
had an inconteffable advantage. This at lead was^Dr. 
Mafkelye’s opinion ; and from this time he appears to 
have taken a diflike to watch-makers. When the pro¬ 
prietors of Dr. Rees’s Cyclopaedia fentan artift to Green¬ 
wich, a few years fince, to requeft the favour of being al¬ 
lowed to examine Harrifon’s time-piece which is there pre¬ 
served, and to make fome drawings from it, Dr. M. would 
not permit any part of it to be infpefled; and, even when 
a queltion was afked as to the portions of parliamentary 
reward which Harrifon had received, a queffion of com¬ 
mon curiofity, and fo eafily anfwered by one who was 
fully acquainted with the whole tranfaclions, “the doCtor, 
with his ufual referve, declined giving any information 
en the fubjeft.” See Chronometer ir. Rees’s Cyclo¬ 
pedia ; and our article Horology, vol. x. p. 349, 355. 
In the year 1764, the office of attronomer royal became 
- vacant by the death of Mr. Blifs, who had furvived his 
appointment, as fucceffor to Dr. Bradley, only two years. 
Dr. Mafkelyne’s celebrity immediately pointed him out 
as the moll competent perfon to fill the Situation. His 
reputation flood very high in the Royal Society, both as 
a profound mathematician and an able allronomer; while 
his experience at fea, and, above all, his fuccefs in efta- 
blifhing the lunar obfervations, feemed to render him pe¬ 
culiarly well qualified to carry into eftefil the purpofe for 
which the Royal Obfervatory had been eftablifhed—that 
of preparing tables for finding the longitude at fea. 
Through want of this knowledge, it was faid, that not 
only fingle Ships, but whole fleets, had been loft, which 
induced government to offer immenfe rewards for practi¬ 
cal methods of determining the problem. When Mr. 
Flamfteed, the firft aftronomer royal, was appointed to 
the office in 1675, he was directed by king Charles II. 
“ to apply himfelf with all diligence to the rectifying the 
tables of the motions of the heavens, and the places of 
the fixed ftars, in order to find out the inuch-defired lon¬ 
gitude at fea, for the perfecting the art of navigation.” 
Thefe were the words of his commiffion, which have been 
Since continued to his fucceffors. Thus, the office of af¬ 
tronomer royal was juftly confidered of great national 
importance ; and Dr. Mafkelyne’s appointment to it, which 
was announced in the London Gazette, Feb. 16, 1765, 
gave univerfal fatisfaCiion. It fhouki be noticed, that 
the office includes a feat at the board of longitude, i. e. 
a board formed of commiflioners, who are appointed “for 
examining, trying, and judging, all propofals, experi¬ 
ments, and improvements, relating to the longitude,” 
- Soon after his appointment, he laid before the Board of 
Longitude the plan of an annual publication, to be enti¬ 
tled the “Nautical Almanac, and Aftronomical Ephe¬ 
mera.” The firft volume was for 17675 and it was con- 
Vol. XIV. No, 988. 
E L Y N £. 47 3 
tinued, under his direction, up to the year 1816, inclti- 
five, making in the whole fifty volumes, a lading monu¬ 
ment of labour and profound learning. It is univerfally 
allowed to be the molt ufeful work on practical aftro- 
nomy ever publifhed. In fuch high estimation has it 
been held by foreign aftronomers, that they have gene¬ 
rally and implicitly adopted its computations, and ac¬ 
knowledged its fuperior accuracy. M. Lalande, in giv¬ 
ing an account of Similar publications, fays, “ LC Nauti¬ 
cal Almanac de Londres eit I’Ephemeride la plus parfaite 
qu’il y ait jamais eu.” 
In 1767, he publifhed an auxiliary work, entitled “ Ta¬ 
bles requifite to be ufed with the Nautical Almanac, in 
order to find the Latitude and Longitude at Sea.” This 
performance, well known to Seamen by the name of “The 
Requifite Tables,” has pafled through feveral editions, 
and has been fuccelfively enlarged, particularly by differ¬ 
ent methods of working the lunar observations, by 
Meflrs. Lyons, Dunthorne, Witchell, Wales, and by Dr. 
Mafkelyne himfelf ; and it has been alfo improved by the 
latitudes and longitudes of places fupplied by captain 
Cook, captain Huddart, MefTrs. Bailey, Wales, and other 
Scientific navigators. Some time after this, he publifhed 
Mayer’s Tables, with both Latin and Englifh explana¬ 
tions, to which he added feveral traCts and tables of his 
own, and prefixed to the whole a Latin preface, with the 
title “Tabulae motuur.i Solis et Lunae, &c.” It was 
publifhed, like the foregoing works, by order of the corn- 
miffioners of longitude ; and the various other publica¬ 
tions iffued by that board during his time were aifo 
printed under his infpeCtion, and are too numerous to 
be here Hated. 
Another important and laborious duty that devolved 
on him in confequence of his qffice was, to examine the 
pretenfions of the various candidates, who claimed the 
parliamentary rewards for new or improved methods of 
finding the longitude. 
It may be obferved, that his appointment took place at 
a period peculiarly interefting in the hiftory of altro- 
nomy, His fuccefs in introducing and promoting the lu¬ 
nar obfervations greatly excited the public attention to the 
fubjeCl of the longitude, which was rendered flill more 
interefting by the great rewards held out by parliament 
for further improvements in the problem, whether by af¬ 
tronomical or mechanical methods. Thefe offers, united 
with the powerful motives of honour and emulation, 
called forth, during feveral years, many extraordinary ef¬ 
forts of genius, and produced ufeful inventions both in 
arts and fciences, and particularly in the conftruction of 
time-keepers. 
The parliamentary offers likevvife encouraged numer¬ 
ous candidates of very flight pretenfions, and even vi- 
fionaries whofe applications became very troublefome. 
The claims of -all were referred by the board of longi¬ 
tude to the aftronomer royal, by whom fcientific plans 
were examined, and the rates of chronometers ascer¬ 
tained. Thus by his office he was conftituted arbiter of 
the fame and fortune of a great number of anxious pro¬ 
jectors j and it is eafy to conceive how arduous as well 
as unpleafant fuch a duty muff have been. It was not 
indeed to be expefted that the fanguine hopes and leif— 
love of fuch a variety of candidates could be gratified, 
with juftice to the high truft and confidence thus repofed 
in him ; and hence complaints were frequently heard, and 
pamphlets publifhed, exprefiive of difeontent and difap- 
pointment. Appeals even were made to parliament ; but, 
whatever difference of opinion might have then exifted, 
time and experience have fince fully proved the truth 
and impartiality of Dr. Mafkelyne’s decifions. 
In giving a general view of his labours at the Royal 
Obfervatory, we fliall begin with his publication of the 
Greenwich Obfervations, which were printed in 1774, by 
command of his majelty. The firft volume began with 
the obfervations of 1765, and they have been continued 
annually fince. M. Lalande, in mentioning this per- 
6 E foimance 
