Thanks to Colin Barnes for sending me a copy of it. See the patent drawings below.
The claims are quite brief--unlike today's patents, they rely heavily on the detailed description in the specification and drawings.
I quote the claims after the drawings.
Having now particularly described and ascertained the nature of my said invention, and in what manner the same is to be performed, I declare that what I claim is:--
1. Calculating apparatus of the kind referred to, in which the cursor is in the form of a sleeve devoid of projections, which is mounted upon the outer member and extends bodily over the telescopic joint on to the inner member, substantially as described.
2. Calculating apparatus as claimed in Claim 1, in which the telescopic joint has its extension limited by the agency of tongues upon one member, such as the resiliently acting tongues B3, which engage an inturned lip or the like, around the edge of the other member, substantially as described.
3. Calculating apparatus as claimed in Claim 1, in which the the cursor has its travel towards the inner member limited by forming at its end an inturned lip adapted to be engaged by tongues, such as A5, provided upon the outer member, substantially as described.
4. Calculating apparatus as claimed in Claim 1, in which the a band of velvet or like resilient material is provided between the sliding surfaces of the inner and outer members, and between the latter and the cursor, substantially as and for the purpose described.
5. Calculating apparatus as claimed in Claim 1, in which the scale-carrying members are closed at their outer ends and an air vent is provided for their interior spaces, preferably extending through a pendant such as B7, to which is attached a ring or the like, substantially as and for the purpose described.
6. The complete calculating apparatus substantially as described or illustrated in the accompanying drawings.