GUNTER. 
cities of London and Westminster, or with- 
in three miles thereof, or within any other 
city, borough, or market-town, or one mile 
thereof, or within two miles of the king’s 
palaces or magazines, or half a iqile of any 
parish church, on pain of forfeiture, and 
two shillings per pound, except in licensed 
mills, or to the amount of three hundred 
pounds for the use of collieries, within two 
hundred yards of them. 
GUNTER (Edmund), an English ma- 
thematician of the seventeenth century, was 
descended from an ancient and I'espectable 
family in Brecknockshire, South Wales, and 
was bora in the county of Herefordshire in 
the year 1580, He received his classical edu- 
cation on the royal foundation at Westmin- 
ster School, whence he was elected at about 
eighteen years of age to Christ Church Col- 
lege, in Oxford, He was admitted to the 
degree of B.A. in 1603, and to that of M.A. 
in 1606; after which he entered into or- 
ders, and proceeded batchelor of divinity in 
the year 1615. His genius had early led 
him to the pursuit of mathematical studies ; 
and at the time when he took his degree of 
M. A. he had merited the title of an inven- 
tor by his new projection of the sector, of 
which he then wrote a description in Latin, 
and permitted his friends to transcribe it, 
though the English account of his invention 
was not published till several years after- 
wards. In the year 1618 he had invented 
a small portable quadrant, for the more 
easy finding the hour and azimuth, and more 
useful astronomical purposes. The reputa- 
tion which he had now acquired in the ma- 
thematical world occasioned his introduc- 
tion to the acquaintance of some of the 
most able mathematicians of his time, by 
whose recommendation and interest he was 
elected professor of astronomy at Gresham 
College, London, in the year 1619. In this 
situation he soon distinguished himself by 
his lectures and his writings, which contri- 
buted greatly to the improvement of science, 
and reflected credit to the choice that had 
been made of him to that professorship. 
His first publication after his election ap- 
peared in 162Q, and was entitled, “ Canon 
Triangulorum, siye Tabulae Sinuum artificia- 
lium ad radium 10.0000000, et ad Scrupula 
prima Quadrantis,” 8vo. This treatise was 
accompanied with the first 1,000 of Brigg’s 
logarithms of common numbers. In the 
second edition of it, which was published 
in English in 1624, under the title of “ Ca- 
non Triangulorum, or Table of artificial 
Signs and Tangents to aradius of 10.0000000 
Parts to each Minute of the Quadrant,” 
4to., the logarithms were continued from 
1,000 to 10,000, and rule was given at the 
end for augmenting them to 100,000. These 
tables were the first of the kind which had 
been given to the world, and, if the author 
had published nothing else, would have pre- 
served his memory to the latest posterity, 
by the admirable aid which they afforded 
to students in astronomy ; for they greatly 
facilitated the practical parts of that science, 
by furnishing a method of solving spherical 
triangles without the aid of secants or versed 
sines ; the same thing being effected by ad- 
dition and subtraction only, which in the 
use of the former tables of right sines and 
tangents required multiplication and divi- 
sion. Due praise was bestowed upon him 
by many of the most eminent mathemati- 
cians among his contemporaries for the ser- 
vice which he rendered to science by this 
most excellent work; and hi$ right to the 
improvement of logarithms, by their appli- 
cation to spherical triangles, was satisfac- 
torily established by Mr. Edmund Wingate, 
Mr. Robert Burton, and Mr. Henry Bond, 
sen. 
In the year 1622 Mr. Gunter made his 
important discovery, that the variation of 
the magnetic needle varies. To this disco- 
very he was led in the course of lectures he 
made on the variation at Deptford, by 
which he found that the declination of the 
needle had changed almost five degrees in 
the space of forty-two years. The truth qf 
this discovery was afterwards confirmed and 
established by Mr. Gellibrand, his successor 
at Gresham College. Soon after this he in- 
vented his famous “ rule of proportion,’’ 
which is an easy and excellent method of 
combining arithmetic and geometry, adapt- 
ed to the understanding of persons of the 
most ordinary capacities, It consists in 
applying the logarithms of numbers and of 
sines and tangents to straight lines drawn 
on a scale or rule, by which, proportions in 
common numbers and trigonometry, may be 
resolved by the mere application of a pair 
of compasses : a method founded on this 
property, that the logarithms of the terms 
of equal ratios are equidifferent. This was 
called Gunter’s proportion and Gunter’s 
line ; and the instrument in the form of a 
two foot scale is now in common use for 
navigation and other purposes, and is com- 
monly called the Gunter. In the year 1624, 
this invention was carried into France by 
Mr. Wingate, who not only communicated 
it to most of the principal mathematician 
