And I thought they were a gathering of the Robert Woolsey fan club!

They are the tins that held the blasting caps that fired the dynamite. I remember my dad had his shot papers to shoot underground dynamite.

A really happy bunch. They get to blow things up!

I have a very similar pair that belonged to my grandfather. He was a machinist during the run-up to WW2. If memory serves me the lenses are ground from quartz. My grandfather's pair has a deep scratch that was caused by something in a metal lathe shattering and the pieces flying everywhere. Better a scratched lens than a missing eye.

These cowboys look like they know how to joke and take a joke. I wouldn't be surprised if they had all put Groucho mustaches under their safety glasses for this picture.

As a longtime snuff chewer, I would agree that those are most likely smokeless tobacco cans, but there's a good possibility that those are rolls of electrical or friction tape, used to splice wire.

Oh wait -- maybe that's why they're all using chewing tobacco.

Snus or snoose would be the local name for what's in those cans; a very common Scandanavian habit here back in the day.

or hockey pucks in their shirts. I'm betting on "Red Man".

Wanted: Blast crew members. Must wear glasses. All others need not apply.

[The identical safety specs they're wearing are indeed mandatory. - Dave]