Front row, L to R: James Clements, James Bigwood MP, William Bradley, Andrew Carnegie LL D, Thomas Layton FSA (Chairman of the Library Committee), Charles James Cross JP, William J Noy, Rev I Parker
Second row: H Payne, Dr Jones, James Bertram (Mr Carnegies private sec.), Dr Joseph S Gubbins, ???, Joseph Thomas Taylor, William George Chovil, Isaac Ward, John Reeder, Edwin Underwood, Fred Turner FR Hist Soc (Librarian), Nowell Parr (Surveyor and designer of the Library and other local buildings), Rev W Edwards, Prof. McNeile Dixon, George Arthur Griffiths, ???
Back row: Archibald Sim Montgomrey JP, Stephen Woodbridge (Town Clerk), Joseph Dorey, Thomas Stallabrass, JW Croxford, George Collier

Biographies for many of the above are available.

You can see the original photo, and many others of Brentford, by visiting Chiswick Library.