|But nothing is simple, because Prof. David cannot risk a direct look through the telescope to see the Sun. Fortunately a sighting tube formed of two circles is there to help our young astronomer. When the shadows of the two circles meet, this means that the lenses of the telescope are aligned on the Sun.|
|A command box controls little motors on the axes and allows the precise centering of the solar image on the cardboard.|
last adjustments, and finally David sees its efforts rewarded. He has
bring out the projection of the Sun on his observation cardboard.
He has to match the solar disk with the pre-drawn circle on the cardboard.