Britannia Tubular Bridge. General plan of works from actual survey, October 1848. [3 items, scale 1" : 100'. Printed by Day & Son. Each plan bears ms. ink additions showing lines used and their links to capstans on the shore either side of Menai Straits; one is "Plan of Floating No.1 or A Tube, Floated 4 Dec 1849"; one is "Plan of Floating No.4 or C Tube, Floated 10 June 1850". These items are available on SM negs. 700/94 to 702/94 and C/T PC-305 to PC-307]