Before Kathryn Johnson became a Physicist & Mathematician responsible for putting men on the moon, she was a teacher and Stay At Home Mom. Later, she applied to NASA to calculate trajectories for space flights.
One page of this compendium is an equatorial sundial, another is a noctural, another a calendar, another a circumferator, compass, alidade and geometric square. From the different pages it is possible to calculate anything from high and low tides and the phases of the moon to the height of buildings. This dial is reputed to have belonged to Sir Francis Drake though this is unconfirmed, and lacks any supporting evidence. Creator: Humfrey Cole Date: 1569
Curta Mechanical Calculator, a small, hand-cranked mechanical calculator introduced by Curt Herzstark in 1948. It can be used to perform addition, subtraction, multiplication, division, and (with more difficulty) square roots and other operations. considered the best portable calculators available until they were displaced by electronic calculators in the 1970s.
The comptometer was the first commercially successful key-driven mechanical calculator, patented in the USA by Dorr E. Felt in 1887. A key-driven calculator is extremely fast because each key adds or subtracts its value to the accumulator as soon as it is pressed and a skilled operator can enter all of the digits of a number simultaneously, using as many fingers as required, making them sometimes faster to use than electronic calculators.