antique lie detector Psychogalvanoscope C.H. Stoelting

NO PAYPAL, sorry. Great find fresh from a university surplus sale. The indicator light comes on and the needle moves,but beyond that I have no idea if it works. I tried to get my kids to test it on them! They were concerned it might really work, so it is going up for sale UNTESTED. I would assume you are buying it for the novelty, or to add to your lie detector collection. T is no model number,but it is engraved "C.H. Stoelting Co. iLL. Chicago 24. I prefer a Postal money order,but other money orders or cashier's check are OK. Payment expected within 10 days of end of auction. Sales ONLY to lower 48 states.Thanks for looking.Actual shipping charges only,,weight 20lb.when packaged.