1. The rules were made in a similar way to Unique rules - that is
paper scales covered by clear plastic.
2. The sine and tan scales, at the top and bottom of the stock, are used respectively with
the A and D scales giving a range from 35' to 90° for the sin scale and 5° 45' for the
tan scale.
3. The tables on the back have densities of wood and metal and a rather unusual table,
shown below, on the relative weights of wood patterns and metal castings for different
woods and metals.
Front view
Detail - front left
Detail - back
