the morning, and if you draw lines from 7 and 8 parallel to _a m_,
their terminations will point out 4 and 5. Six o'clock is in the very
corner opposite to 6 in the evening. Parallel lines below the
transverse piece drawn from 5, 4, 3, will indicate the proper places
for 7, 8, 9. It then remains to set off the same distances as before
on line _l k_ on which the shadow of _m_ will point out 11, 10, and 9
o'clock; the dial will then be finished.

_Observe._ These dials require considerable thickness (_let it be
equal to a m_,) because being placed parallel to the equator, the sun
shines upon the upper face till the summer, and on the longest day is
elevated 23° 29' above the plane of the dial, and consequently the
shadow of _a_ will fall at noon in the line _a b_, not in the point
_b_, but at an angle of 23° 29' therewith, and on the shortest day the
like angle will be formed, but in an opposite direction. It must
further be observed that after the proper points are determined on the
plane, they had better be transferred to the sides of the cross, as is
shown in _fig._ 2, for there it is the shadow will be seen to pass. A
dial thus formed is universal; when made according to the foregoing
directions there is nothing more to do but to fix it by the help of
your quadrant to the elevation of the equinoctial or complement of the
latitude of your habitation, and so that the side _a m_ may exactly
face the south. A dial of this sort has been standing in my garden,
more than 12 months, and is found to answer the purpose well, being
both useful and ornamental.

When the figures are painted on the thickness as in _fig._ 2, the
upper surface being unoccupied, an equinoctial dial may be described
thereon, which will be useful the summer half year, while on the lower
surface a similar one may be placed for the winter half; or it may be