As there are unlikely to be very few who will recall the roof of the Hall this is the description from Francis White's History & General Directory of the Borough of Birmingham of 1849:
"The roof is composed of a lantern middle part for air and light, and has fifty-six windows on each side, and five at each end, with seventeen large sky-lights at the top and two side parts of the common angular construction, which have seventeen sky-lights each. The whole is sustained by seventeen series of beams, which are supported by seventeen pairs of iron pillars, twenty-eight feet high and twenty feet apart."
Must have been quite a sight. Viv.