JAMES SHORT LONDON 250/1103= 9.5 (engraved on the end of the body tube). 16 (written on a small self adhesive label, discarded). MANU SHORT,James circa 1759 Surry-Street, The Strand, London, England DES after CASSEGRAIN,Jacques, or Guillome, or N. 1672 France. DES after DIGGES,Leonard circa 1550 Wooten Court, Kent, England. This 2.5" aperture Cassegrain reflecting telescope, by James Short, has an altazimuth mounting on a pillar and claw stand. The primary mirror is concave and the secondary convex. The advantage of the Cassegrain telescope over the Gregorian is that it has an equivalent magnifying power at half the length.