I recall pallets from the

I recall pallets from the 1930s in materials handling info from the Soo Line that was still in the Stores Dept files in the 1980s.  Can't help you on the vent.

Re Roof Vents

I am currently leafing through my 1942 Architectural Forum bound edition. So far I've come across advertisements for two other roof vents that function on the same principle but have a different appearance. But I am about 99% sure that the type you have were in use by then. Still looking though. 

From

From http://en.wikipedia.org/wiki/Pallet

See the entry here:  http://en.wikipedia.org/wiki/Forklift_truck for the history of the forklift...

The device shown in the photo is a Turbine Vent, not a Hurricane Vent. The Hurricane vent is a specific design, distinguished by its flat sides, and claims higher efficiency.

Useful Information

That is useful information, I always suspected that the palette and forklift were a recent invention. At least too recent for my 1920's era!

The vent

I believe the vent you have pictured is a turbine vent. As the warm air rises and exits the vent, it causes the vent to spin. As wind on the outside causes the turbine to spin, air is vented though the resulting suction created with the spinning. Having seen these, as I recall, as a youth, I would say they have been around for better than 65 years.

There are vents similar in function to the turbine vents, but have additional shielding on the outside to resist hurricane force winds.

Thanks, guys. Pallets are

Thanks, guys. Pallets are good, but still unsure on the vents...

@ Lee

You might want to check out Shorpy.  There are plenty of roof top pics throughout.  You might spot the vents in use that you want to model.

http://www.shorpy.com

Den

1921 U.S. patent for a ventilating device

This 1921 patent filing might show the grand-daddy of many that came later:

https://www.google.com/patents/US1509957

So, I think that there would be no problem in them being around in 1943. I have them on my 1939 time-period module.

@chepp

Great job of research. That pretty well narrows it down.

That style of vent was on the

That style of vent was on the barn where I grew up.  It was build sometime between 39 and 46, depending on whom you talked to.

-Doug

thanks!

Thanks for the info, i had no idea they went back that far...

P51...thanks

51, thanks for posting these two great questions.  I too have had similar questions.  The replies are what I love most about MRH!

...

Early forklifts were essentially add-on parts for base tractors, whereas instead of a backhoe, you have a forklift.