## 985

Example-: 2hI0m Mem Solar Time Equals: 2h = Oml9.713s Sid. Time 1 On = Om 1.6^3s Sid. Time

Let us assume a birth occurred at 7;30 A.M. We use the Sidereal Time 0/ the previous day given in rhe' Ephemeris, add 10 it first 12 hours to get us to midnight (the Sidereal Time in the Ephemeris is usually figured for Noon) , then we add the extra 7h30m to get us to the birth moment at 7:30 A.M. Since the Sidereal Time has kept on moving at the rate of 3 minutes 56.555 seconds each 24 hours, we have to add to this Sidereal Time that amount of sidereal motion which was produced between the previous Noon and the time of 7:30 A.M. Here we have to add the Sidereal Time motion of 19' hours 30 minutes. We eitheruse a flat increment of 10 seconds for each hour elapsed since the previous Noon, or else, we use our Table III and take the value from it:

19 hours equals 3m7.273s (Sid. motion in 19 hours) H- 4.928s {Sid. motion in 30 minutes)

### 3ml2.2-01s

A small adjustment, also, is necessary on account of the distance of the various places from Greenwich. This adjustment is called the "Reduction from Greenwich to local Sidereal Time" which is expressed in seconds and which is fo-und in the last column in Table IX. This reduction is minus (— when the birch place is to the East of Greenwich) and plus (+) when the place of birth is West of Greenwich. It amounts to 1 second for every iy2 degrees in Longitude -4- or — (West ox East).

At all times we must use the Standard Time of a place. In the event a city or region uses Daylight Saving Time, we have to turn it into Standard Time. Special adjustments must be made during war rimes, when clocks are moved ahead quite a bit to save daylight hoars! Verify each case!