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.
Fact
If your heart muscle was required to work filling beer bottles in a brewery, it would be able to fill 1,600 crates of beer daily with 30 bottles each. And it would work, without requiring any repairs, for 70 years. .. More >>