''It is true that "Nothing is more practical than a theory" Provided - however - That the assumptions on which the theory is founded Are well understood. - But, indeed, engineering experience shows that "Nothing can be more disastrous than a theory When applied to a real problem Outside of the practicailimits of the assumptions made", Because of an homonymous identity With the problem under consideration. " (J. T. P. ) The primary objective of this work is to present the theories of analytical and optical isodynes and the related measurement procedures in a manner com­ patible with the modem scientific methodology and with the requirements of modem technology pertaining to the usefulness of the stress analysis proce­ dures. The selected examples illustrate some major theses of this work and demonstrate the particular