[Gorzaloon]

You can test it with an infrared thermocam and a tube full of CO2 - the CO2 will block out and absorb heat. The politics of global warming are another matter, but don’t try and deny a basic fact of science.

I think the description was poorly written or the experiment was poorly designed.

They never discussed the "check valve effect". The salt plate will transmit back out the longer wavelengths from reradiation better than the glass model. By interposing glass before the salt plate, the experimenter blocked the longer wavelengths beyond glass's cutoff.

IR Spectrometery was not in any serious use till the 1940's, and as late as the 1960's IR Imaging was primitive.

1909 was a long, long way from FLIR. I would be tempted to dissmiss the work as a well-intentioned quaint attempt at understanding, like the Ether Theory and Spontaneous Generation of microorganisms, myself.

[chipengineer]

>By interposing glass before the salt plate, the experimenter blocked the longer wavelengths beyond glass’s cutoff.

Thais possible, but I hope the experimenter put that glass plate far enough away so that the solid angle presented to the emitter was small.

My explanation is that this experiment was still seeing all the natural greenhouse gases between the apparatus and cold space, so the natural greenhouse effect was never eliminated.