Also the wedge shape of a train rail switch, where one rail crosses another
is called a frog.

"Josh" wrote in message
oups.com...
If he's flying first class, he's usually called "Sir" or "Mr. Frog".

Leonard Bailey, the original inventor, never mentions the name "Frog"
in his patent in 1858. Later after Stanley bought him out, Traut
patented an improved lateral adjustment where he mentions the "frog",
but he gives no clue as to the origin of the term.

A horse's hoof has a wedge-shaped structure called a frog. Maybe it
was the similarity in shape?

Josh


TWS wrote:
Can anyone give me the reason a 'frog' is called a frog?

Thanks in advance,
TWS