  This is a translation from Latin to Portuguese of Euler's 'Attempt at a
theory of the friction of fluids'. According to the records, a treatise by
Euler with the title 'Tentamen theoriae de frictione fluidorum' was presented
to the St. Petersburg Academy on June 17, 1754, and perhaps was read to the
Berlin Academy on December 2, 1751. In this treatise, Euler assumes that as for
the solid friction, the fluid friction is proportional to the applied normal
force. A detailed development of five different problems of discharge are
presented in his treatise, taking into account the loss of head in the
conduits. In the appendix, an example is given for the calculation of the jet
heights of a particular fountain, fed with conduits of different amplitudes.
