Again
| hour | minute | second | |
| At 1 hr. 30 min. mean clock shows | 5 | 20 | 0 siderial |
| Right ascension of Venus | 2 | 10 | 0 |
| --- | --- | --- | |
| Set hour circle to | 3 | 10 | 0 |
Books may be found in libraries that will give the right ascension and declination of most of the heavenly bodies.
The foregoing tables assume that you have a clock rated to siderial time, but this is not absolutely necessary. If you can obtain the planet's declination on the day of observation and ascertain when it is due south, all you have to do is to set the pointer D by the needle point and note whether Venus has passed your meridian or not and set your hour index. There will be no difficulty in picking up Venus even in bright sunlight when the planet is visible to the naked eye.
Electric Light Turned On and Off from Different Places
The Wiring Diagram
How nice it would be to have an electric light at the turn in a stairway, or at the top that could be turned on before starting up the stair and on reaching the top turned out, and vice versa when coming down. The wiring diagram as shown in the illustration will make this a pleasant reality. This wiring may be applied in numerous like instances. The electric globe may be located at any desired place and the two point switches are connected in series with the source of current as shown in the sketch. The light may be turned on or off at either one of the switches.
Contributed by Robert W. Hall, New Haven, Conn.