

GUNTER. 



to most of the principal mathematicians 

 then at Paris, but also, at their request, 

 published an account of it in the French 

 language. Mr. Gunter likewise greatly 

 improved the sector, and other instru- 

 ments for the same uses, the description 

 fall which he published in 16.H, in a 

 treatise, entitled " The Cross Staff, in 

 three books," &c. 4lo. In the same year 

 he published, by King James's order, a 

 small tract, entitled " The Description 

 and Use of his Majestie's Dials in White- 

 hall Garden," 4to. Mr. Gunter had been 

 employed by the direction of King 

 Charles in drawing the lines on these 

 dials, and at his desire wrote this descrip- 

 tion, 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 lo- 

 garithmical arithmetic; 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 corresponding ordi- 

 nates. To him likewise the mathemati- 

 cal world is indebted for many other in- 

 rentions and improvements, most of 

 which were the subjects of his lectures at 

 Gresham College, and afterwards dispos- 

 ed into treatises, which were printed in 

 his works. From the genius and abilities 

 which he had displayed in his works al- 

 ready* 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, however, will 

 be transmitted with honour to posterity, 

 as that of the parent of instrumental 

 arithmetic. His works have been collect- 

 ed, and various editions of them have 

 been published. The fifth is by William 

 J.eybourn, in 1673, 4to. containing the de- 

 scription and use of the sector, cross- 

 staff, bow, quadrant, and other instru- 

 ments ; with several pieces added by 

 Samuel Foster, Henry Bond, and William 

 Leybourn. 



GUTTER'S chain, the chain in common 

 yse 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 5 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 in- 

 to acres. The reason 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 there- 

 fore 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 multi- 

 plying by 4 and 40. But the better way 

 is to set the dimensions down in links, as 

 integers, considering each chain as 100 

 links; then having multiplied the dimen- 

 sions together, producing 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 are* 

 we say 



887 



750 



44350 

 6209 



6.65250 

 4 



2.61000 

 40 



24.4 

 The contents are 6 A. 2 R. 24 P. 



GUTTER'S line, a logarithmic line, usu- 

 ally graduated upon scales, sectors, &c. 

 It is also called the line of lines and line 

 of numbers ; being only the logarithms 

 graduated upon a ruler, which therefore 

 serves to solve problems instrumentally, 

 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 1 

 with 10 ; so that if the first great division 

 marked 1, stand for one tenth of any in- 

 teger, the next division, marked 2, will 

 stand for two-tenths; 3, three-tenths, 

 and soon ; 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 will 

 the lesser divisions stand for integers ; 

 and if the great divisions be supposed 

 each 100, the subdivisions will be each 

 10. 



GUTTER'S line, use of. 1. tf To find the 

 prpduct of two numbers 1 ." From 1 ex- 



