Abbe’s Principle of Alignment

The Abbe’s principle of alignment is named after the German Professor Earnst Abbe. In 1890, he proposed a set of rules for taking linear measurements.   His principle consists of the following 3 points :   1. For best results, a linear reading should be taken...

Airy Points and Bessel Points

When simply supported at finite number of points, a beam will bend under its own weight. The shape it takes depends on the spacing between the supports and the cross-sectional and micro-structural uniformity of the beam. Airy Points Sir George Biddell Airy  showed...