"Any ideas what this is? It has fine tuning double dials on the front, uses a lissen grid bias battery, turned up in a vintage collection."
A: "That is an old am radio. There is a connector on the right rear corner for hooking up headphone or speaker. Those wouldn’t have produced very much sound and were usually used with an old style single sided headphone. One dial is course tune and the other is fine tune. The antenna is that little tube with the green wire wrapped around it. Also on the back at the bottom, there were sometimes connectors for external antenna but don’t hook up to the wrong ones. It fairly easy to test and figure if you know anything about electronics."
"Small metal screw with hole in end that second flat screw screws into – possibly to do with picture hanging with a picture rail"
A: "Its for wire. It gets threaded through the hole and the secondary screw holds it into place."
"Found this thing on a german graveyard on nearly every grave – What is this little ‘bowl’-like thing? There was also a little metal-stick in it."
A: "It‘s 100% that The stick is a sprinkler for holy water. Apparently it’s called Aspergillum"
"Odd Switch on Wall, turned it last night and now their is an odd vibrating noice coming from the ceiling."
A: "Timer switch for a fan/light, typically found in bathrooms for exhaust fans or heat lamps."
"Heavy rounded plastic from the beach, warnings in English and French, seems like it was part of a sphere?"
A: "Firework shell."
"Small “Big Cat” token. Found while cleaning out childhood bedroom"
A: "It’s from a First Robotics team. 3039 is Wildcat Robotics. It’s probably something they made to give out at competitions."
"Metal and glass. Top has magnifying lens and comes off. ca 1870, Germany."
A: "It’s called a seed microscope."
"Green remote with 2 metal prongs and a radiant “I” as a registered trademark on the device. Donated to the library, possibly as a coding tool?"
A: "Farmtech bot anne. Its a robot. The metal prongs are dc motors, probably for locomotion."
"Some sort of looking glass? Wood end pieces, metal middle, glass lenses on both sides. Comes apart. When you look through, you see upside down."
A: "It’s an antique field pocket microscope."
"My apartment builder fixed this random looking thing on the roof .Not sure what it is and what it does. It was recently fixed and I’m not sure if it is anything significant. Can anyone fill in my curiosity."
A: "It’s a reflector for surveying. Most likely used to determine building movement/settling over time."
"Ammunition with a weird shiny tip, could be 30mm? Worried If inert or not. Found on glacier in Swiss."
A: "Do not handle suspected UXO under any circumstances."
"A large capsule like device found in a London food court, there were 6 of them all in close proximity to each other and were all entirely silent. Probably about a foot long and 6 inches in diameter."
A: "It’s a pretty expensive speaker."
"WITT seems to be a very thick optical line"
A: "Fiber optic line for a light fixture. They’re used in locations where you can’t have a spark or heat, or need a particularly small light source that puts out a lot of light."
"WITT some sort of small black electronic device with wires coming out of it. More info in the captions."
A: "It’s the sounder for reverse parking sensors. The button will turn it on or off or change the tone."
"White crystallised substance forming square patterns. Big clump of it on one slide, randomly appeared in glass."
A: "Almost certainly salt. Good ol’ NaCl, or table salt."
"What is this small metal piece sticking out on our staircase? It’s about 3 inches tall and the protruding piece doesn’t move."
A: "It’s where you tie off an old drying line to set the height."
"What is this heavy piece of glass? It has six “cups” to put something in and the bottom is cone shapes."
A: "It’s a tea light candle holder."
"Odd extension to house eaves in central London – maybe some kind of gantry"
A: "Looks like one of the old style sign hangers, like for a pub or shop."
"Looks like one of the old style sign hangers, like for a pub or shop."
A: "Salt and pepper shaker"
"5 inch tall plastic object found in a back office. The “pump” can be depressed onto a thin metal rod connected at the base."
A: "That is a “safety” version of a memo/recept spike. You put the ticket or recept on the rod and push the top down punching the paper onto the rod."
"Small metal item. Probably chrome or stainless steel."
A: "It’s the leg from an articulated bear keychain."
See? That wasn't hard.
Let me jump in here with a layman's explanation, It's a Keychains that has an articulated bear attachment, I'll be back next week with more facts for your delectation.