The halogen or krypton bulbs in modern torches (USA and Canada: flashlights) have a limited life and are not particularly cheap. A simple modification in the torch lengthens the life appreciably. It ...

This is why all outdoor stores need their very own darkrooms along with those nubby climbing walls and fake rocky inclines. A pitch-black place to compare flashlights. As you point out, what used to ...

In 1,000,000 quarts of air there is one quart of krypton. An inert gas discovered in 1898 by Ramsay and Travers, krypton is scarcer and less volatile than argon, neon and xenon; its name means “the ...