Use Of Dials:
The graphic ephemeris comes with 3 dial settings: 360, 180, and 90 degrees:
The 360 degree dial will draw planets lines according to their actual positions. The advantage of this dial is that you can see easily where the planets actually are in the zodiac circle, but it's disadvantage is that it becomes harder to see exact aspects like the opposition and square that are very important. Oppositions and conjunctions are detected using the 180 degree dial and conjunctions, squares or oppositions are shown by the 90 degree dial. The way these other 2 dials work is that if a planet is at 23 degrees Scorpio (233 degrees) on date X, then 180 degrees is subtracted from 233 to arrive at 53 degrees on a 180 degree dial. If it is a 90 degree dial then 90 degrees is subtracted twice until the degree value is less then the dial value. The advantage of these other 2 dials is that crossing lines represent exact aspects, but the disadvantage is you don't know where they are exactly until you click on the graph.