In article ,
Tom Anderson wrote:
On Thu, 15 Feb 2007, BH Williams wrote:

A raised centre section to the roof, in the side of which may be either
glass windows or sometimes ventilator louvres. They were a common
feature of 19th century carriage design.- perhaps as a means of
'borrowing' light for the middle of compartments.

Having thought about this - (a) was this before they'd thought of
skylights and (b) what was the point of putting such a thing on the
engine, rather than the passenger carriages?

I think clerestory carriage roofs were introduced when gas lighting was
still common, maybe even oil. I think the Midland had gas by the 1870s
or 1880s, but I can't find the book to check exactly when clerestories
came in - I'm sure it was well before the turn of the century. It must
have been a good way to get the smell and ventilation of the lamps up
away from the passengers.

Nick
--
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