Rodents are of the orderRodentia, characterised by a single pair of continuously growing incisors in each of the upper and lower jaws that must be kept short by gnawing.
Arthur Casagrande (August 28, 1902 – September 6, 1981) was an Austrian-born American civil engineer who made important contributions to the fields of engineering geology and geotechnical engineering during its infancy. Renowned for his ingenious designs of soil testing apparatus and fundamental research on and soil liquefaction, he is also credited for developing the soil mechanics teaching programme at Harvard University during the early 1930s that has since been modelled in many universities around th..