English Dictionary

umbra versa

/ˈʌmbɹə ˈvɜːsə/

noun

On a shadow in the shape of a right triangle, the length of the shadow's edge opposite to a measured angle.

The umbra versa cast a right triangle shadow on the ground.

意味（1）

On a shadow in the shape of a right triangle, the length of the shadow's edge opposite to a measured angle.

Scheubelius a great Mathematician, but by book only, and not by practice who being required ſometime in an Army to make uſe of his Quadrant, knew not the difference between umbra recta, and umbra verſa.