These rifles were of a white metal stocked with wood, which I learned later was a very light and intensely hard growth much prized on Mars, and entirely unknown to us denizens of Earth. The metal of the barrel is an alloy composed principally of aluminum and steel which they have learned to temper to a hardness far exceeding that of the steel with which we are familiar. The weight of these rifles is comparatively little, and with the small caliber, explosive, radium projectiles which they use, and the great length of the barrel, they are deadly in the extreme and at ranges which would be unthinkable on Earth. The theoretic effective radius of this rifle is three hundred miles, but the best they can do in actual service when equipped with their wireless finders and sighters is but a trifle over two hundred miles.