Hydrometer and saccharometer

Bate's hydrometer.

Robert Brettell Bate had a profitable business selling scientific instruments of all kinds. With the collaboration of Royal Society scientists he worked to improve the hydrometer, and was later asked to make models for the new standard weights and measures enacted by parliament in 1825. This was one of several hydrometers tested by the Society's Excise Committee in the early 19th century. 

Bate's saccharometer.