A printed circuit board (PCB) is a core unit of an electronic device with electronic parts mounted on a circuit board. The electronic parts conduct appropriate amounts of current or electric signals ...

WE are very doubtful whether the first portion of this book, dealing with the practical construction of a microscope by the amateur, will serve any useful purpose. Such an instrument, however well ...

Hey folks! I figured this would be best in the observatory. I'm relearning how to use microscopes and learning for the first time how to really use them more effectively, so that I can show my ...