Bink's burettes and a Wollaston slide rule, 1814.
© Science Museum / Science & Society Picture Library
A burette is a device for delivering a variable, known volume of liquid. In their earliest forms, such as the type designed by Gay-Lusac (1778-1850) for his volumetric method of estimating silver by titration with chloride, the flow was controlled by placing a thumb over the wide end. The Gay-Lusac burette is shown second on the right. With Binks's burette, control was by a thumb placed over a side tube. A Binks's burette is being used to titrate silver nitrate in the photograph. Another Binks's burette is shown on the right. It was once owned by the famous dye firm of Simpson & Maule. William Hyde Wollaston's (1766-1828) slide rule was used for quick calculations of the weights of substances reacting with each other. An example is shown in the left foreground.