I 
GUN 
then at Paris, but also, at their request, 
published an account of it in the French 
language; Mr. Gunter likewise greatly im- 
proved the sector, and other instruments 
for the same uses, tiie description of all 
which he published in 1624, in a treatise 
entitled “ The Cross Staff, in three Books,” 
&c. 4to. In the same year he published, 
by King James’s order, a small tract, en- 
titled, “ The Description and Use of his 
Majestie’s Dials in Whitehall Garden,” 4to. 
Mr. Gunter had been employed by the di- 
rection of King Charles in drawing the lines 
on these dials, and at his desire wrote this 
description, to which we refer those readers 
who wish to see a particular account of the 
construction and uses of those dials, which 
are no longer in existence. Our author 
was the first who used the word co-sine for 
the sine of the complement of an arc. He 
also introduced the use of arithmetical 
complements into the logarithmical arith- 
metic ; and it has been said, that he first 
started the idea of the logarithmic curve, 
which was so called because the segments 
of its axis are the logarithms of the corres- 
ponding ordinates. To him likewise the 
mathematical world is indebted for many 
other inventions and improvements, most of 
which were the subjects of his lectures at 
Gresham College, and afterwards disposed 
into treatises, which were printed in his works. 
From the genius and abilities which he had 
displayed in his works already noticed, the 
highest expectations were formed of his 
future services in the cause of useful science ; 
but they were unhappily disappointed by 
his death, in 1626, when he was only in the 
forty-fifth year of his age. His name, how- 
ever. will be transmitted with honour to 
posterity, as that of the parent of instru- 
mental arithmetic. His works have been 
collected, and various editions of them have 
been published. The fifth is by William 
Leybourn, in 1673, 4to., containing the 
description and use of the sector, cross-staff, 
bow, quadrant, and other instruments ; With 
several pieces added by Samuel Foster, 
Henry Bond, and William Leybourn. 
Gunter’s chain, the chain in common 
use for measuring land, according to true 
or statute measure; so called from Mr. 
Gunter, its reputed inventor. The length 
of the chain is 66 feet, or 22 yards, or 4 poles, 
of 51 yards each ; and it is divided into 100 
links, of 7.92 inches each. This chain is the 
most convenient of any thing for measuring 
land, because the contents thence computed 
are so easily turned into acres. The reason 
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of which is, that an acre of land is just equal 
to 10 square chains, or 10 chains in length 
and one in breadth, or equal to 100,000 
square links. Hence, the dimensions being 
taken in chains, and multiplied together, 
it gives the content in square chains, which 
therefore being divided by 10, or a figure 
cut off for decimals, brings the content to 
acres ; after which the decimals are reduced 
to roods and perches, by multiplying by 4 
and 40. But the better way is to set the 
dimensions down in links, as integers, con- 
sidering each chain as 100 links ; then, hav- 
ing multiplied the dimensions together, pro- 
ducing square links, divide these by 100,000, 
that is, cut off five places for decimals, the 
rest are acres, and the decimals are reduced 
to roods and perches as before. Suppose 
a field to be measured be 887 links in 
length, and 750 in breadth, to find its area 
we say 887 
750 
44350 
6209 
6.65250 
4 
2.61000 
40 
24.4 
The contents are 6 A. 'ill. 24 P. 
Gunter’s line, a logarithmic line, usu- 
ally graduated upon scales, sectors, &c. It 
is also called the line of lines, and line of 
numbed ; being only the logarithms gradu- 
ated upon a ruler, which therefore serves to 
solve problems instrnmentally in the same 
manner as logarithms do arithmetically. It 
is usually divided into an hundred parts, 
every tenth thereof is numbered, beginning 
with 1 , and ending with 10; so that if the 
first great division, marked 1, stand for one 
tenth of any integer, the next division, 
marked 2, will stand for two-tenths ; 3, three- 
tenths, and so on ; and the intermediate 
divisions will, in like manner, represent 
100th parts of the same integer. If each 
of the great divisions represent 10 integers, 
then \yill the lesser divisions stand for in- 
tegers; and if the great divisions be sup- 
posed each 100, the subdivisions will be 
each 10. 
Gunter’s line, use of. 1. “ To find the 
product of two numbers." From 1 extend 
the compasses to the multiplier ; and the 
same extent, applied the same way from 
the multiplicand, will reach to the product, 
Thus, if the product of 4 and 8 be required, 
extend the compasses from 1 to 4, and that 
