12-18 years

Telescope in the pocket

Kesulitan: ★

Making your own sky disk

Kesulitan: ★

Form the armillary sphere to the astrolabe

Kesulitan: ★

The pyrenean shepherd’s dials

Kesulitan: ★

Building simple sundials

Kesulitan: ★

Latitude Gnomon and Guadrant for the Whole Year

Kesulitan: ★

Making helioscopes with four sticks

Kesulitan: ★