This page has been validated.
122
spherules, supposing the least distance of distinct vision to be 7 inches, and the object to be placed (l) at the focus, (2) at the least distance for distinct vision.
Focal length in terms of an inch. |
No. of times that the length of the object is magnified. |
No. of times that the surface is magnified. | ||
1 | 7. | 8. | 49 | 64 |
.75 | 9.33 | 10.33 | 87 | 107 |
.50 | 14. | 15. | 196 | 225 |
.40 | 17.50 | 18.50 | 306 | 342 |
.30 | 23.33 | 24.33 | 544 | 592 |
.20 | 35. | 36. | 1225 | 1296 |
.15 | 46.66 | 47.66 | 2181 | 2276 |
.10 | 70. | 71. | 4900 | 5401 |
.05 | 140. | 141. | 19600 | 19881 |
.03 | 233.33 | 234.33 | 54289 | 54912 |
.02 | 350. | 351. | 122500 | 123201 |
.01 | 700. | 701. | 490000 | 491401 |
The next Table is for a person whose least distance of correct vision is 5 inches.
Focal length in terms of an inch. |
No. of times that the length is magnified. |
No. of times that the surface is magnified. | ||
1 | 5. | 6. | 25 | 36 |
.75 | 6.67 | 7.67 | 44 | 58 |
.50 | 10.00 | 11.00 | 100 | 121 |
.40 | 12.50 | 13.50 | 156 | 195 |
.30 | 16.67 | 17.67 | 278 | 312 |
.20 | 25.60 | 26.00 | 625 | 676 |
.15 | 33.33 | 34.33 | 1111 | 1179 |
.10 | 50.00 | 51.00 | 2500 | 2601 |
.05 | 100.00 | 101.00 | 10000 | 10201 |
.03 | 166.67 | 167.67 | 27779 | 28110 |
.02 | 250.00 | 251.00 | 62500 | 62901 |
.01 | 500.00 | 501.00 | 250000 | 251001 |