Editing Steam engine (section)

===Governor===
{{Main|Governor (device)}}
[[File:Boulton and Watt centrifugal governor-MJ.jpg|thumb|upright=0.8|right|[[Centrifugal governor]] in the [[Boulton & Watt engine]] 1788 [[Lap Engine]].]]

The [[centrifugal governor]] was adopted by James Watt for use on a steam engine in 1788 after Watt's partner Boulton saw one on the equipment of a flour mill [[Boulton & Watt]] were building.<ref>
{{cite book
|title=A History of Control Engineering 1800–1930
 |last1=Bennett
 |first1= S.
|year=1979 |publisher =Peter Peregrinus Ltd.
|location= London
|isbn= 978-0-86341-047-5
}}
</ref> The governor could not actually hold a set speed, because it would assume a new constant speed in response to load changes. The governor was able to handle smaller variations such as those caused by fluctuating heat load to the boiler. Also, there was a tendency for oscillation whenever there was a speed change. As a consequence, engines equipped only with this governor were not suitable for operations requiring constant speed, such as cotton spinning.<ref>{{Harvnb|Bennett|1979|pp=}}</ref> The governor was improved over time and coupled with variable steam cut off, good speed control in response to changes in load was attainable near the end of the 19th century.