Posted by Bruce Kahl on November 01, 2000
In Reply to: Set the Thames on fire posted by Brian on November 01, 2000
: What is the origin of the phrase "He/They won't set the Thames on fire"
Not sure of the exact origin of your phrase but the sense of the phrase goes way back.
The phase "to set the Thames on fire", appeared in common usage in the late 18th century, and has always been used as an ironic expression to describe someone who is lethargic, simple minded, or lacks enterprise. "I hardly expect him to set the Thames on fire; but I hope his mother will never have reason to be ashamed of him..." (W. E. Norris).
There is also a similar Latin saying but using the River Tiber--"Tiberim accendre nequaquam potest"
And the Rhine--"Er hat den Rhein und das Meer angezündet"