culated for the same latitude. Such a dial can
therefore not be used near Edinburgh or Glasgow, although it would,
without appreciable error, be adapted to any place whose latitude did
not differ more than 20 or 30 m. from that of London, and it would be
safe to employ it in Essex, Kent or Wiltshire.

If a series of such dials were constructed, differing by 30 m. in
latitude, then an intending purchaser could select one adapted to a
place whose latitude was within 15 m. of his own, and the error of
time would never exceed a small fraction of a minute. The following
table will enable us to check the accuracy of the hour-lines and of
the angle of the style,--all angles on the dial being readily measured
with an ordinary protractor. It extends from 50 deg. lat. to 59 1/2 deg.
lat., and therefore includes the whole of Great Britain and Ireland:--

+--------+--------+--------+---------+----------+---------+--------+
| LAT. |XI. A.M.| X. A.M.| IX. A.M.|VIII. A.M.|VII. A.M.|VI. A.M.|
| | I. P.M.|II. P.M.|III. P.M.|IIII. P.M.| V. P.M.|VI. P.M.|
| | | | | | | |
|deg. |deg. |deg. | deg. | deg. | deg. |deg. |
| min.| min.| min.| min.| min.| min.| min.|
+--------+--------+--------+---------+----------+---------+--------+
| 50 0 | 11 36 | 23 51 | 37 27 | 53 0 | 70 43 | 90 0 |
| 50 30 | 11 41 | 24 1 | 37 39 | 53 12 | 70 51 | 90 0 |
| 51 0 | 11 46 | 24 10 | 37 51 | 53 23 | 70 59 | 90 0 |
| 51 30 | 11 51 | 24 19 | 38 3 | 53 35 | 71 6 | 90 0 |
| 52 0 | 11 55 | 24 28 | 38 14 | 53 46 | 71 13 | 90 0 |
| 52 30 | 12 0 | 24 37 | 38 25 | 53 57 | 71 20 | 90 0 |
| 53 0 | 12 5 | 24 45 | 38 37 | 54 8 | 71 27 | 90 0 |
| 53 30 | 12 9 | 24 54 | 38 48 | 54 19 | 71 34 | 90 0 |
| 54 0 | 12 14 | 25 2 | 38 58 | 54 29 | 71 40 | 90 0 |
| 54 30 | 12 18 | 25 10 | 39 9 | 54 39 | 71 47 | 90 0 |
| 55 0 | 12 23 | 25 19 | 39 19 | 54 49 | 71 53 | 90 0 |
| 55 30 | 12 27 | 25 27 | 39 30 | 54 59 | 71 59 | 90 0 |
| 56 0 | 12 31 | 25 35 | 39 40 | 55 9 | 72 5 | 90 0 |
| 56 30 | 12 36 | 25 43 | 39 50 | 55 18 | 72 11 | 90 0 |
| 57 0 | 12 40 | 25 50 | 39 59 | 55 27 | 72 17 | 90 0 |
| 57 30 | 12 44 |