History of Timekeeping Devices

http://www.historyofwatch.com/clock-history/timekeeping-devices-history/

History of Horology

https://www.govbergwatches.com/blog/history-of-horology/

Clock and Watch History

http://www.historyofwatch.com/

Wrist Watches From Battlefield to Fashion Accessory

https://www.nytimes.com/2013/10/23/fashion/wrist-watches-from-battlefield-to-fashion-accessory.html

The Hourglass

https://www.uh.edu/engines/epi1469.htm

First hourglass

http://www.guinnessworldrecords.com/world-records/first-hourglass

A Brief History of the Wristwatch

https://www.theatlantic.com/international/archive/2015/05/history-wristwatch-apple-watch/391424/

O Relógio atômico Brasileiro

http://www.cepa.if.usp.br/e-fisica/mecanica/pesquisahoje/cap3/defaultframebaixo.htm

Início de 15 milissegundos que levou a US $ 28 milhões em negócios

https://qz.com/91242/the-15-millisecond-head-start-that-led-to-28-million-in-trades/

Huygens slingerklok

https://www.youtube.com/watch?v=1I_9egHXe3I