Bharatiya Jyotihshastra (History of Indian Astronomy), translated by R. V. Vaidya v2.c12.s5.63

v2.c12.s5.63

Gaṇeśa Daivajña, the author of the Grahalāghava, compiled this work on instruments. It contains 13 chapters. The author claims that even while riding a horse one can find time by observation with the help of this Pratoda yantra, and also the shadow cast by the gnomon at that time. Its construction is not described here for want of space. Sakhārāma and Gopinātha have written commentaries on this work.