_ 
1809.] Memoirs of Henry Briggs, the Mathematician. 277 
ealculation to others, and particularly to 
Mr. Briggs; but he did not live te go 
through what he intended, and, there- 
fore, after his decease, the MS. being 
sent to Mr. Briggs, he made several 
additions to it, as will appear by the 
following contents of the book itself. 
1. Mirifici logurithmorum canonis con- 
structio, et eorumad naturales ipsorum 
numeros habvitudines. 
2. Appendix de alia et prestantiori lo- 
garithmorum specie construenda, in qua 
scilicet unitatis logarithmus est 0. 
3. Lucubraiones aliquot dactissimi 
D. Henrici Briggii in Appendicem pre- 
MUSSAI, . 
- 4, Propositiones quedaum eminentissime 
ad triangula spherica mira facilitate re- 
solvenda. . : 
5. Annotationes aliquot -doctissimi D, 
Henrici Briggii in Propositiones pre- 
MISSUS. 
Concerning these pieces, the edi- 
tor has given the following account 
in his Preface:—‘* Lucubrationes ali- 
quot mathematici excellentissimi D. Hen- 
rici Briggii, publici apud Londinenses 
professoris, in memoratas - Propositiones 
et novam hance logarithmorum speciem, 
typis inandari curavimus ; qui novi hujus 
Ganonis supputandi laborem — gravissi- 
mum pro singulari amicitia que illi cum 
patre meo intercessit, animo libentissimo 
In se suscepit; creandi methodo, et 
usuum explanatione, inventor? relictis. 
Nunc autem, ipso ex hac vita evocato, to- 
tius negotil onus doctissimi Brigg hume- 
ris incumbere, et Sparta hec ornanda, illi 
seorte quadam obtigisse videtur.”* From 
this account it appears, that, the Baron 
not living to finish what he had under- 
taken, in relation to the new logarithms, 
not only the labour of calculating them, 
but the other part also, came’now to be 
devolved upon Mr. Briggs; both which 
he admirably well performed afterwards 
in his Arithmetica Logarithmica. But.as 
the Baron had before claimed to himself 
the invention of these logarithms, so we 
find that his son here repeats. the same 
claim ; and therefore it may be proper 
to hear in what manner Mr. Briggs him- 
‘self relates this matter, in his Preface to 
his book last-mentioned, where he pro- 
fessedly treats of it. His words are 
these: Quad logarithmi isti diversi sunt ub 
ts, quos clarissimus vir Buro Marchisto- 
ali in suo edidit Canone Mirifico, non 
est quod mireris. Ego enim, cum meis audi- 
toribus Londini, publico in Collegio Gres- 
‘  * Edinburgi, 1619, 4te 
Moxtury Mae, No. 190. 
hamensi horum doctrinam explicarem anie 
madverttymulto futurum commoduis ; st 
logarithmus sinus totius servaretur O, ut in 
Canone Mirifico ; logarithmus autem par- 
tis decime ejusdem sinus totius, nempe 
smus 5 graduum 44 m. 21 s. esset 
1,0000000000. Atgue ea de re scripst 
statim ad ipsum autorem, et quam primum 
per anni tempus, et vucalionem a publico 
docendi munere licuit, profectus sum Edin- 
burgum, ubt humanissime ab eo acceptus 
hast per integrum.mensem, Cum autem 
inter nos de horum mutatione sermo ha- 
beretur, wlle se idem dudum sensisse et 
cupivisse dicebat, veruntamen istos quogs 
jum paraverat, edendos curasse donec 
altos, si per negotia et valetudinem lice- 
ret, magis commodos perfecissit. Istam au- 
tem mutationem ita faciendam  cense- 
bat; ut O esset logarithmus unitatis, et 
1,0000000000_ sinus lotius, quod ega 
longe commodissimum esse, non potui non 
agnoscere. Capi igitur ejus hortatuy 
rejectis illis quos antea paraverum, de hae 
rum calcula serio-cogiturt. Et -sequenti 
estate tterum profectus Edinburgum ho- 
rum, quos hic exhibeo, precipues ill ose 
tendi, idem etiam teriza estate libentissime 
facturus, sti Deus illum nobis tam din 
superstitem esse voluisset. 
From this relation it appears, that in 
1615, Mr. Briggs, in explaining the sub- 
ject of logarithms to his hearers at Gres- 
ham College, as delivered in the Canon 
Mirificus, observed, it would be more 
commodious, if they were so altered, 
that O should be the logarithm of the 
whole sine, as in the. Canon, and 
1,0000000000 be made the logarithm 
of the tenth part of the whole sine, viz. 
5° 44/21”; and presently after, he ac- 
quainted the author.of this by a letter; 
and having calculated some logarithms 
after that manner, in the year 1616, 
after his lectures in Trinity .Term, he 
took a journey_to Edinburgh to pay him 
a visit, and shew him what he had done. 
He was very kindly received by the 
Baron, and stayed with him a month: 
and in their conversation upon that 
head, the Baron told him, he was sen- 
sible the logarithms might be altered for 
the better, before he published his Ca- 
non, but chose to have them printed 
in the manner he had prepared them, 
till he had leisure and health to make 
others more* commodious, which he 
thought would be best, if O were 
made the logarithm af an unit, and 
1,0000000000 that of the whole sine, 
Mr. Briggs agreed with him in this 5 and 
at his desire, after he came back to Lon- 
2.9 don, 
