A metal ruler with centre section (53 mm) wide that slides away from the base. Above the slide on the base is a number scale from 0 to 70. On the slide is written "Solent MK 4 Loading Slide Rule". A sketch of the sections of the airplane is also there with some parts labelled "Pantry". Below, are numerous other number scales labelled as parts of the plane, e.g. "Cabin D". The back of the base has a long oval hole though which a scale is visible from beneath. The hole is surrounded by more number scales. In the bottom left corner is written "Locate the arrow below the derived index no. read off C.G. opposite the A.U.W. in kilos." In the middle of the ruler is affixed a piece of clear plastic 36 mm wide with a line down the centre. This plastic piece also slides. There is a grey leather case, rectangular with a triangular flap over one of the short ends. That flap can be closed with a metal snap inside the flap. Written in pen is "P.D. Kilgair".
Slide Rule (Solent Mk 4 Loading), 1965.468. The Museum of Transport and Technology (MOTAT).