Editing Timer (section)

===Mechanical===
Mechanical timers use [[clockwork]] to measure time.<ref name="Sobey">{{cite book 
 | last = [[Ed Sobey|Sobey]]
 | first = Ed 
 | title = The Way Kitchens Work: The Science Behind the Microwave, Teflon Pan, Garbage Disposal, and More 
 | publisher = Chicago Review Press
 | year = 2021
 | location = UK
 | pages = 161–164
 | url = https://books.google.com/books?id=RDfCMTQPMucC&q=%22timer%22+%22balance+wheel%22&pg=PA164
 | isbn = 978-1569762813}}</ref> Manual timers are typically set by turning a dial to the time interval desired, turning the dial stores energy in a [[mainspring]] to run the mechanism. They function similarly to a mechanical [[alarm clock]], the energy in the mainspring causes a [[balance wheel]] to rotate back and forth. Each swing of the wheel releases the gear train to move forward by a small fixed amount, causing the dial to move steadily backward until it reaches zero when a lever arm strikes a bell. The mechanical kitchen timer was invented in 1926.

The simplest and oldest type of mechanical timer is the hourglass - which is also known as "the glass of the hour" - in which a fixed amount of sand drains through a narrow opening from one chamber to another to measure a time interval.