Johann Bernoulli was a Swiss mathematician and was one of the many prominent mathematicians in the Bernoulli family. He is known for his contributions to infinitesimal calculus and educating Leonhard Euler in the pupil's youth.
Johann Bernoulli (portrait by Johann Rudolf Huber, c. 1740)
Commercium philosophicum et mathematicum (1745), a collection of letters between Leibnitz and Bernoulli
Illustration from De motu corporum gravium published in Acta Eruditorum, 1713
Volumes I-IV of Bernoulli's 1742 Opera Omnia
Leonhard Euler was a Swiss mathematician, physicist, astronomer, geographer, logician, and engineer who founded the studies of graph theory and topology and made pioneering and influential discoveries in many other branches of mathematics such as analytic number theory, complex analysis, and infinitesimal calculus. He introduced much of modern mathematical terminology and notation, including the notion of a mathematical function. He is also known for his work in mechanics, fluid dynamics, optics, astronomy, and music theory.
Portrait by Jakob Emanuel Handmann, 1753
1957 Soviet Union stamp commemorating the 250th birthday of Euler. The text says: 250 years from the birth of the great mathematician, academician Leonhard Euler.
Euler's grave at the Alexander Nevsky Monastery
Euler portrait on the sixth series of the 10 Franc banknote
