This is the carving above the main entrance of David Kirkaldy's "Testing and Experimenting Works" in Southwark, London. He believed in testing built-up structures rather than just the materials of which they are made, if you wanted to know how they behaved. In this, he was a pioneer, and dead right, too.

These works did a lot of the testing of sections of the Tay Railway Bridge which collapsed in 1879.