(Laghu Samrat Yantra)
Jantar Mantar Observatory
The gnomon (ramp) of this sundial points directly towards the North Pole, so local Jaipur time can be read off from the position of the gnomon's shadow on the fine divisions of its curved scale. The photograph on the next page shows the scale in closeup.
Yantra means "instrument" (it is the same word as "jantar"), and a Samrat Yantra is a sundial.