+----------------------------------------------------------------+ |Latitude.| Factor. |||Temperature|Tension.||Temperature|Tension.| | | ||| of Vapour.| || of Vapour.| | |---------+---------+++-----------+--------++-----------+--------| |Degrees. | ||| Degrees. |Inches. || Degrees. |Inches. | | 0 | 0.99735 ||| 179 | 14.934 || 197 | 22.036 | | 5 | 0.99739 ||| 180 | 15.271 || 198 | 22.501 | | 10 | 0.99751 ||| 181 | 15.614 || 199 | 22.974 | | 15 | 0.99770 ||| 182 | 15.963 || 200 | 23.456 | | 20 | 0.99797 ||| 183 | 16.318 || 201 | 23.946 | | 25 | 0.99830 ||| 184 | 16.680 || 202 | 24.445 | | 30 | 0.99868 ||| 185 | 17.049 || 203 | 24.952 | | 35 | 0.99910 ||| 186 | 17.425 || 204 | 25.468 | | 40 | 0.99954 ||| 187 | 17.808 || 205 | 25.993 | | 45 | 1.00000 ||| 188 | 18.197 || 206 | 26.527 | | 50 | 1.00046 ||| 189 | 18.594 || 207 | 27.070 | | 55 | 1.00090 ||| 190 | 18.998 || 208 | 27.623 | | 60 | 1.00132 ||| 191 | 19.409 || 209 | 28.185 | | 65 | 1.00170 ||| 192 | 19.828 || 210 | 28.756 | | 70 | 1.00203 ||| 193 | 20.254 || 211 | 29.335 | | 75 | 1.00230 ||| 194 | 20.688 || 212 | 29.922 | | 80 | 1.00249 ||| 195 | 21.129 || 213 | 30.515 | | | ||| 196 | 21.578 || 214 | 31.115 | +----------------------------------------------------------------+ _How to use the Tables._--When the _temperature_ is known to decimals of a degree, take out the tension for the degree, and multiply the difference between it and the next tension by the decimals of the temperature, and add the product to the tension, for the degree. Required the tension corresponding to 197 deg.84. deg. 197 = 22.036 .465 x .84 = .391 198 = 22.501 197 deg. = 22.036 ------ ------ Difference .465 197.84 = 22.427 ====== ====== When the _tension_ is given, take the difference between it and the next less tension in the Table, and divide this difference by the difference between the next less and next greater tensions. The quotient will be the decimals to add to the degree opposite the next less tension. Thus, for 23.214 inches, required the temperature.