The era of compact and portable mechanical chronometers opened the invention are the same Huygens in 1675 rotary actuator, as well as the use of weights instead of springs. Compound torsion pendulum, a spiral spring and anchor running paved the way not only to marine navigation, but also the creation of massive small hours, but still significantly increased the accuracy of astronomical observations, and even found the uneven rotation of the Earth. Read the rest of this entry »