A set of 'Scale Rules'

"This is a set of 'Scale Rules' typically used by Architects and Engineers and students of Technical Drawing up to 1960s. The scale are in in feet and inches and as such predate the introduction of decimal drawings. A set contained eight paper rulers each with two different scale measures giving a total of sixteen scales for different types of drawings. The set was supplied by the 'educational Company of Ireland' and could be bought in the likes of Easons etc."