It will be perceived from above that the mantissa remains unaltered so long as the numbers consist of the same significant figures: change the numbers and the mantissa must also change. Examples, The reverse of the foregoing rule holds good in every particular, i. e. having sought in the the tables of logarithms for the number corresponding to the given mantissa, the index will determine the number of digits in the integral part. 88 30 1 45 101 Examples for Practice. 1. Required the logarithm of the following numbers,— 7200 43710 39906 400000 6754 •1463 ⚫00647 3.874 18.006 36 7 21 20 8 40 Find the log tangent of 22 20 11 20 30 15 29 11 40 Find the log co-secant of 45 8 29 127 30 40 82 5 Find the arc to the log. sine of ⚫0046 2.374900 3.100300 1.610432 4.000710 5.001476 170° 30' 39" 1° 49' 47" 40 56 0 50 88 108 59 19 40 7 1 2 18 58 43 37 71 43 9 8 39 3 7 10. Multiply 7000 by 1 by logs. 11. Multiply 476 by 682 by logs. 12. Multiply 3746 by 6168 by logs and decimals. 13. Find the product of 38, 174, 96, and 0756, by logs 14. Find the product of 376, 0069, and 1·476 by logs. 15. Find the product of 2-4, 008, 62 and 3.1. 16. Divide 66 by 3 by logs. 17. Divide 777 by 11 by logs. 18. Divide 1728 by 144 by logs. Divide 1000 by 1000 by logs. 20. Divide 1010 by 101 by logs. 19. 22. Divide 37 by 02 by logs. and decimals. 23. Divide 76 by 874 by logs. 24. Divide 10 by 5.86 by logs. and decimals. 25. Divide 6748 by 00763 by logs. 26. Divide 34761 by 2.674 by logs and decimals. 27. Required the square of 46, of 94, of ∙163 and of 0075 by logs. 28. Required the cube of 47, of 63, of 109 and of 00861 by logs. 29. Required the square root of 4796, of 746937 and of 6470, by logs. 30. Required the cube root of 36472, of 62154 and of 7564 by logs. 31. What is the cost of 243 yards at 9s. 3 d. per yard, by logs and decimals. 32. What is the cost of 3 tons 2 cwt. 3 qrs. at 4s. 6d. for 7lbs. by logs. 33. If 100 yards cost £70. 15s. what does 1 foot cost at the same rate? 34. If of a lb. cost 4s. 8d. what will 27 lbs. cost? DAYS WORKS. Lee Way Remarks. P.M. I take my departure from a point of land in Lat 34° 51'S. Long 20o 2′E. bearing by compass N. N. W. W. distant 17 miles. East. N.N.E. A.M E.N.E.E. North. N.N.W. N.E. A current sets W. by S. by compass at the rate of 2 miles per hour. Variation 2 pts. W Lee Way Remarks. P.M. I take my departure from a point of land, in Lat. 40° 29'N. Long. 124° 32'W bearing by compass E. & S. distant 17 miles. 60 70 S.S.W. 6 6 W.S.W. 10 11 N.W. N.N.E. 12 A.M. 7 W.N.W. 0 6 6 S.E.b.E. N.E.b.E. A current set E.N.E. by compass 14 miles during the last 10 hours. |