rules have been duly published in the Proceedings of this Society for I883, page 200. The result of the effort to obtain copies of the Standard will be given in detail by the custodian, Prof. Geo. E.

The capability of a vernier or digital caliper depends on the accuracy of the scale. A caliper's design, rigidity of the beam, squareness and parallelism of the jaws to the scale, and general ...