4, containing a history and bibliography of Black Hills investigations); also R.
His writings include: Mathematical Investigations in the Theory of Value and Prices (1892); Elements of Geometry (with A.
For a long time the final result deduced by Joule by these varied and careful investigations was accepted as the standard value of the mechanical equivalent of heat.
All these older methods have, however, been thrown into the background and rendered antiquated by inventions which have grown out of Hertz's scientific investigations on the production of electric waves.
Another group of investigations that seems to play an important part in the future development of the theory of evolution relates to the study of what is known as organic symmetry.