Projection of Straight Line Apparatus.
The lines connecting the hinges represent plan and elevation of the straight line. Also the main rod made of two unit can be made to tilt about hinges and to test on H.P. and V.P. to illustrate the method of finding true length of a line by suitable construction either on H.P. or V.P. Suitable hinges are provided between H.P. or V.P. so that it can be folded and will be found to be quite compact for use in a class room.
Consists of a straight rod placed in the space formed in between two
perpendicular planes representing a straight line standing in between
H.P. and V.P. and also hinged to both planes by thin rods.