Pants hemming tool - photo

[Altair]

Pants hemming tool.




Previously:

https://www.homemadetools.net/forum/...046#post120348
Making a hat on a sewing machine - GIF
Sewing gauge for even button spacing - photo
Industrial sewing machine in slow motion - GIF
Victorian sewing kit - photo

[IntheGroove]

I recall one of those in our house when i was a kid...

[IntheGroove]

And these pinking shears were always near...

[Toolmaker51]

While these would work for trousers, the real intent is women's skirts. It wouldn't work very well other than chalking a pant leg, since most of us have our feet in the way.
The hinged arm has a small guide 'notch' that corresponds where it engages the upright section. This guides a straight pin accurately, which were typically headed with small glass spheres. A row of pins in circumference of dress hem set the height according to scale on the tool. Then, clothing was ready to sew on a machine, knowing the result was parallel to floor.
Before I knew what a height gauge was, Mom's was occasionally employed marking waterline on model boat hulls. Years [decades] later my wife was amazed I knew what it was, let alone how to work it, and set her hems for re-enactment clothing. "Well Maria, it IS after-all a tool..."
Good times can take many forms of activity!

[IntheGroove]

Apparently your grandfather was not a tailor...