TABLE, SHOWING THE NUMBER OF DAYS FROM ANY DAY OF ONE MONTH TO THE SAME DAY OF ANY OTHER MONTH IN THE SAME YEAR. FROM ANY DAY OF JANUARY, FEBRUARY, MARCH, APRIL, MAY, JUNE, JULY, AUGUST, TO THE SAME DAY OF Jan. Feb. Mar. Ap'l May June July Aug. Sept. Oct. Nov. Dec. 92 123 153 184 214 61 92 122 153 183 365 31 59 90 120 151 181 212 243 273 304 334 334 365 28 59 89 120 150 181 212 242 273 303 306 337 365 31 61 92 122 153 184 214 245 275 275 306 334 365 30 61 91 122 153 183 214 244 245 276 304 335 365 31 61 214 245 273 304 334 365 30 184 215 243 274 304 335 365 31 62 92 123 153 153 184 212 243 273 304 334 365 31 61 92122 SEPTEMBER, 122 153 181 212 242 273 303 334 365 30 61 91 OCTOBER, 92 123 151 182 212 243 273 304 335 365 31 61 NOVEMBER, 61 92 120 151 181 212 242 273 304 334 365 30 DECEMBER, 31 62 90 121 151 182 212 243 274 304 335 365 As an example, suppose we wish the number of days from November 6th to the 15th of next April. We find November in the left-hand vertical column, and April at the top line of the table, and at the intersection we find 151 days. So that from November 6th to April 6th is 151 days; consequently, adding 9, we find 160 for the number of days between November 6th and April 15th. This table is constructed on the supposition of 28 days to February. When there are 29 days in February the proper allowance must be made. EXAMPLES. 1. How many days from May 3d to the 4th of the next July? Ans. 62 days. 2. How many days from July 4th to the 25th of the next December? Ans. 174 days. 3. How many days from March 21st to the 23d of the next September? Ans. 186 days. 4. How many days from September 23d to the 21st of the next March? Ans. 179 days. 5. How many days from June 21st to the 22d of the next December? Ans. 184 days. 6. How many days from December 22d to the 21st of the next June ? Ans. 181 days. 7. How many days from March 21st to the 21st of the next June? Ans. 92 days. 8. How many days from Jan. 13th, 1848, to September 17th of the same year? Ans. 248 days. CIRCULAR MEASURE, OR MOTION. 77. By this is estimated Latitude and Longitude, and the motion of the heavenly bodies which appear to move in circles. Every circle, whether great or small, is divided into 360 degrees. The sun appears to pass completely around the earth in 24 hours, that is, it appears to move westward over 360° of longitude in 24 hours. Consequently, in one hour it will move over 24 of 360° 15° of longitude. Hence, if the difference in the longitudes of two places is 150, it will be noon at the more easterly place, just one hour before it is noon at the other place. And in all cases, the difference in time of any two places will be at the rate of one hour for every 15° of longitude between the two places. As an example, suppose the city of Washington to be 77° west of Greenwich: it is required to find what time it is at Washington, when it is noon at Greenwich. Dividing 770 by 150 we have 5 for the number of hours difference in time, that is, 5h. 8m. And as the apparent motion of the sun is westward, it must be earlier at Washington than at Greenwich. Therefore, when it is noon at Greenwich, it is 5h. 8m. before noon at Washington; that is, it is at Washington 6h. 52m. A. M. What use is made of Circular Motion? Into how many degrees are all circles supposed to be divided? Repeat the Table. Over how many degrees of longitude does the sun appear to move in 24 hours? Over how many degrees in 1 hour? What is the difference of time corresponding to 770? When it is noon at Greenwich, what time is it at Washington, 770 west of Greenwich? 78. Measures, &c., not included in the foregoing tables. 6 points make 1 line 1 inch used in measuring length of clock pendulum rods. 1 hand used in measuring the height of horses. used in measuring depths at sea. 79. A sheet folded into two leaves is called a folio. folded into four leaves is called a quarto, or 4to. 66 folded into eight leaves is called an octavo, or 8vo. folded into twelve leaves is called a duodecimo, or 12mo. folded into eighteen leaves is called an 18mo. When a sheet is folded into two leaves what is it called? How called when folded into four leaves? How, when folded into eight leaves? How, when folded into twelve leaves? How, when folded into eighteen leaves? REDUCTION. 80. REDUCTION is the changing of numbers from one name or denomination to another, without altering their value. When the denominations are to be reduced from a higher denomination to a lower, it is called Reduction Descending; but when they are to be reduced from a lower to a higher denomination, it is called Reduction Ascending. REDUCTION DESCENDING. Let it be required to reduce £7 5s. 10d. 3 far. to farthings. OPERATION. 7 the number of pounds. Multiply by 20, the number of shillings in one pound. 140 product in shillings. Add 5 shillings. 145 the number of shillings. Multiply by 12, the number of pence in one shilling. 290 145 1740 product in pence. Add 10 pence. 1750 the number of pence. Multiply by 4, the number of farthings in one penny. Add 7000 product in farthings. 3 farthings. 7003 the number of farthings sought. From the above operation, we readily deduce this general RULE. Multiply the number in the highest denomination by the number indicating how many of the next lower make one in |