The leading article of the June number of the _Century Magazine_ is entitled “The Problem of increasing Human Energy,” and is written by Nikola Tesla. Mr. Tesla offers the reader some naive verbal analogies between the causes of human progress and the ‘energy’ of theoretical physics, and a eulogy of a number of inventions which he expects to make. He intersperses these with sundry remarkable statements such as, “our own earth will be a lump of ice;” “Though this movement is not of a translatory character, yet the general laws of mechanical movement are applicable to it;” “That we can send a message to a planet is certain, that we can get an answer is probable;” “It is highly probable that if there are intelligent beings on Mars they have long ago realized this very idea [the transmission of electrical energy for industrial purposes without wires], _which would explain the changes on its surface noted by astronomers_.” (The italics are our own.) Mr. Tesla’s doctrine of human energy is in some ways as original as the inventions and discoveries which he expects to make. Each of us is, he says, a part of a unitary whole, ‘man.’ “This one human being lives on and on.... Therein ... is to be found the partial explanation of many of those marvelous phenomena of heredity which are the result of countless centuries of feeble but persistent influence.” Now we may “assume that human energy is measured by half the product of man’s mass with the square of a certain hypothetical velocity ... the great problem of science is, and always will be, to increase the energy thus defined.... This mass is impelled in one direction by a force F, which is resisted by another partly frictional and partly negative force R, acting in a direction exactly opposite, and retarding the movement of the mass.” Unhappily Mr. Tesla in his enthusiasm to progress to recommendations of religion, vegetarianism, the old régime for women and the artificial preparation of nitrogen compounds, neglects to state which direction is the proper one for the human mass to follow, north, south, east, west, toward the moon or Sirius or to Dante’s Satan in the centre of the earth. Nor does he explain how ‘enlightenment’ makes the mass of human bodies go in an exactly opposite direction to that toward which ‘visionariness’ impels them, nor reveal why, if his account be true, he and a ‘visionary’ can walk in the same direction. Of course the whole notion that the ‘velocity’ of the human ‘mass,’ _i.e._ the space it traverses in a given time, has any connection with human progress or is of any value to anybody or anything, is absurd.