282 
HINTS TO TRAVELLERS. 
TABLE XXIV. 
Useful Constants and Numbers. 
Ratio of circumference to diameter of a circle . - jr - 5 ■ 141592653590. 
Log t r = 0-497149872694. 
= 1*772451850906. 
— 180° -4-7T = 10800' -i-7r = 648000" - 4 - 77. 
log = i 758122652409. 
log = 5-556275882795. 
log = 5 * 514425155176. 
log = 2-5625810. 
log = 2-5625978. 
log 1-002 = 0-0011874. 
log 0-997 = 9-9988126. 
log = 2-4429091. 
log 5-5144251. 
log 5*5*62759. 
log 1-7581226. 
77 2 = 9 • 869604401089 . 
Arc of same length as radius. 
180 0 - 4 -7T = 57°‘29577951*0 . 
10800' 4 - 7r = 5437 '* 7467707849. 
648000" -4-7r = 206264"-8062470964. 
Tropical year = 565d. 5I1. 48m. 47s.-588 = 565d.-242217456 
Sidereal year= 565d. 6h. 9m. ios.*742 = 565d.-256574552 
24h. sol. t. = 24I1. 5m. 56s.-555555 sid. t. = 24b. X 1*00275791 
24b. sid. t. = 24h. — (5m. 55s.-90944) sol. t. = 24h. X 0-9972696 
British Imperial gallon = 277-274 cubic inches.. 
10 lbs. of distilled water at 62° F. = 1 gallon. 
Length of sec. pend, in inches, at London, 59*15929; Paris, 59-1285; New York, 59-1285. 
French metre = 5-2808992 English feet = 59*3707904 inches. 
1 cubic inch of water (bar. 50 inches Fahr. therm. 62°) = 252-458 Troy grains. 
Radius reduced to seconds = 206264-8. 
,, ,, minutes = 5457-74677 . 
,, ,, degrees = 57-295780. 
No. of Sexagesimal degrees in a Centesimal degree = 0-9. log 1-9542425. 
No. of Sexagesimal minutes in a Centesimal minute = 0-54 log 1-7525958. 
No. of Sexagesimal seconds in a Centesimal second = o- 524. log 1-5105450. 
No. of feet in a statute mile =5280 log 5-7226559. 
No. of feet in a geographical mile = 6075-6. log 5-7855892. 
German square miles x by 21-9 = English square miles. 
English square miles -j- by 21-9 = German square miles. 
Russian square verst -j- by 2-2 = English square miles. 
English square miles X by 2-2 = Russian square versts.* 
The square of the distance in statute miles — ^ of it = correction for curvature and refraction, in feet. 
Diurnal acceleration of stars (= 5m. 55s.-9095) expressed in mean solar seconds = 255-9095 
Jog 2*372744** 
Sidereal day (= 25b. 56111. 4s. -09) expressed in mean solar days = 0-99726967 .. log 1-9908127. 
Mean solar day (= 24I1. 5111. 56s.-5554) expressed in sidereal days = 1-00275791 log 0-0011874. 
No. of French metres in a toise = 1 -949040. log 0-2898127. 
No. of English yards in a Fren h toise = 2-1515*08. log 0-5286916. 
No. of Engl sh feet in a French toise = 6-5945925. log 0-8058128. 
1 Gunter’s chain = 66 feet. 
80 Gunter’s chains = 1 statute mile. 
Links X 22 = yards. 
Links x 66 = feet. 
To find the solidity of a cylinder , multiply the square of the diameter of 
its base by 0*7854, and the product multiplied by the perpendicular 
height of the cylinder will be its solidity. 
* For the conversion of various foreign measures into English equivalents, see explanation Of 
Table XXI. 
