The description and use of an universal and perpetual mathematical instrument ... shewing the most expeditious and exact method of solving all practical questions in arithmetick, trigonometry, navigation, dyalling, astronomy, &c. ... / by Benjamin Scott.

Scott, Benjamin, -1755.

Date:: 1733

Credit: The description and use of an universal and perpetual mathematical instrument ... shewing the most expeditious and exact method of solving all practical questions in arithmetick, trigonometry, navigation, dyalling, astronomy, &c. ... / by Benjamin Scott. Source: Wellcome Collection.

67/144 page 49

$OrERATION. Set the Hair B, to the Hours} APS at | Hout Sine of 90, andthe Hair A | |thePole) Diftan to the Sine of 38° 28 (itbe- {12 | o oo} 0 o ing the Complement of the UE SAG) 2:26 given Latitude 51° 32’) ; 21 7 30] 4 41 tothis opening {crew the SEEE SSF nd two Legs of the Se¢tor faft, | 1 -]15 9} _9 28 and move the Hair B to cut I 15° in the 'Tangents, and 2 then doth the Hair A cut 3 Matie ‘Tangent. of 9° 2573.) 2_: which is the Diftance of the I hour Lines of 1 and 11 2137 30|25 32 _ from the Subftile or twelve 3141 15|28 38 -oClock ; and thus by the | 3_ +45 0/3! 54 I 2 3 ues I 2 3 i ’ 18 45 |11 56 22 30/14 27 26 1§|17 4 130 OO} 19 45 33. ANAS Inftrument you may exa- 48 45135 22 _mine this Table, or make $2 30|19 3, another for any given Place. 56 15/42 58 : I fuppofe my Readst to be 160 0147 9 acquainted with Dialling, 63 45|51 36 -fo I fhall forbear to fhew 67 30/56 20 how to delineate the hour 7I 1§/6r 23 Lines when calculated, er 175 0/66 42 ‘the making of any other 1178 45|72 17 Dial, becaufe that is not 2182 30178 3 3 my prefent Defign, but to 86 15184 o thew only the Ufe of the 16.90 0'90 0 Anitrament. , E vt The$