[brando]

Water is naturally clear, and the perception of colour is dependant on particles suspended in it and light reflected from it. Therefore it's also dependant on time of day, nature of weather, and state of tide. (The Thames is tidal all the way up to Teddington lock) Thus the river looks browner as the tide goes out and the mudbanks are exposed - with the other extreme being altogether dependant on sunlight, cloud cover, blueness of sky and so on.

I wouldn't want to rely on hand-coloured photos or some of the cine-film which seems to have more garish hues than reality. Suffice to say that at full tide on a sunny day it looks at its best, but it never obtains the Mediterannean blue that the tourist photos suggest.

As far as the models are concerned, they look great! My request is to reproduce the drab result of over fifty years of unremitting coal smoke which polluted all of the buildings in London. Tower Bridge as modelled looks entirely convincing, just too clean and bright.

B