Were WW1 period scopes waterproof?

[Kiwi]

Were any British ww1 period scopes waterproof or would they have been prone to moisture intrusion and consequential fogging up when climatic conditions changed? ? I have three Aldis Brothers 1916 scopes, a Westley and Richards scope, and recently acquired a a PPCo Model 1918 scope and none of them appear are what I would call sealed units.

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[Peter Laidler]

Absolutely not......... We used to say that they were like waterproof army wristwatches. Remember them, with WWW on the rear for Watches, Wristlet, Waterproof? They were waterproof in that they'd let the water IN, but wouldn't let it OUT again. Same as your telescopes

[Surpmil]

And the Winchester A5 has an elongated hole in the side of the tube if you please.

Good thing it rarely rained in France.

Dr. Common's telescopic sight for the long Lee Enfield may have been a sealed unit; the only effective way to make a waterproof scope in those days was to have a fixed reticule and external adjustments as his did.

The Warner & Swasey thus had at least that much going for it.

[browningautorifle]

the Winchester A5 has an elongated hole in the side of the tube

Which I'm guessing is to allow for changes in atmospheric pressures?

[Surpmil]

Which I'm guessing is to allow for changes in atmospheric pressures?

It's quite a few years since I had one apart, but IIRC the screw head in the elongated hole locks the erector cell in location. The screw head has a reverse taper which pushes against the inside of the hole or slot, so you turn the screw counter-clockwise to lock the cell.

[CINDERS]

That A5 scope would be great in a dust bowl like Africa or in the Solomons where there is not much humidity