1857 October 17, “Observation and Inference”, in The Entomologist's Weekly Intelligencer[1], volume 3, number 55, E. Newman, page 17:
We are not not going to discuss the causes which have induced the Vectesian agriculturalists to arrive at this conclusion;[…]
1947, Cuthbert Hamilton Ellis, The Trains We Loved[2], Allen:
The first stretch of Vectesian railway to be encountered by most visitors from London belonged to none of the island railways.
2005 August 27, Tony Davison, “Re:back”, in uk.misc[3] (Usenet):
When did you last go to the IOW. Its been there donkeys years.¶ Probably what makes people scream when they use it and notice the signs of Vectisian maintenance,[sic]