Scientific Instruments & Appliances mariner's compass is an apparatus for determining direction, graduated to indicate 33 directions. the "n" point on the dial indicates north pole and the "s" point, south pole.
Scientific Instruments & Appliances periscope is an apparatus for viewing objects lying above the eye level of the observer and whose direct vision is obstructed.
Scientific Instruments & Appliances salinometer is a type of hydrometer used to determine the concentration of salt solutions by measuring their densities.
World Record Facts
The youngest person to have a full set of false teeth was only 4 years old. He suffered from an inherited disease that destroyed his teeth. .. More >>