Cross staff is an instrument used for ............

An ideal vertical curve to join two gradients, is ............

To instrument resembling an alidade is ............

The projection of a traverse line on a line perpendicular to the meridian is known as ............

The instrument used to reproduce plans to a different scale is called ............

Magnetic declination at any place ............

The fundamental principle of surveying is to work from the ............

Can the vertical axis coincide with any other axis in any position of telescope?

Diurnal variation of magnetic declination is ............