Elgin Grade 81

 This is an older one...

Here is the ratchet wheel and click, located under the dial.

The serial number is stamped on all the major parts.

This movement is an Elgin G.M. Wheeler model, a name Elgin used on better watches throughout its 100 year history. For more examples, see here.

Specifically, this one is a grade 81, 18 size, 13-15 jewels, made about 1879.