As surprised no one in the entire universe - this or any other - Henry is somewhat immediately halted by the lamps. He actually stops, physically, although presumably it is not long before Ewar notices this and gently prods, or whatever, because he is used to academic weirdos.

Henry is used to like, 21st century technology and as such notes the absence of cold much less than he would if it was as drafty as a castle ought to be. Although he has spent some time in Britain, and you can't swing your arms without hitting a castle there, so he has visited at least one. (It was the Tower of London, ftlog; that does not count.)