I live in Nazareth, pa Looking for info on this tandem bike. emblem on front is from Davis Sewing Machine company, Dayton, Ohio. Is missing one seat. Has rims but no tires. what kind of tires were used?
Are those wooden rims? If so I'd imagine it was made to use single tube tires (the tire and inner tube are all one inseparable piece, unlike a normal bike tire), probably 28" ones. I have no idea where you'd find any as I think they haven't been made for decades.
Edit: if they do indeed take 28" tires, apparently Coker Tire has them? But You might want to try asking around http://thecabe.com/vbulletin/content.php for specific information on finding tires for a bike this old.
Nice! The tires can be found but are quite costly. If you are looking to do a proper restoration be prepared to pay. If you want to just make it a rider consider these 28" rims. The tires are easily available and will maintain the correct look of the bike.