A combined sun & star diagonal, designed by Alexander Clarkson, made by W. Watson & Sons of London, circa 1900.

R.A.S. standard 1 1/4 inch thread.

With associated parts.

Marked: "SUN" & "STAR" DIAGONAL. - W.WATSON & SONS, LONDON.

9 x 7 x 4.5 cm.

For more information on combined sun and star diagonal see the paper written by Chris Lord: http://www.brayebrookobservatory.org/BrayObsWebSite/HOMEPAGE/PageMill_Resources/SUN&STAR_DIAGONAL.pdf