These facilities are mainly in instruments of measurements and research. So many of these are there now, that it would only complicate matters to enumerate them and describe their spheres. Two of the most important are the spectroscope and the photographic camera. By means of the spectroscope, the astronomer can ascertain the chemical elements of far distant stars, the temperature and pressure under which they exist, the stage of progress of the star, and its speed and direction of movement, whether toward us or away. By means of the photographic camera, not only can records be made of stars so far away and faint that light-waves from them cannot be noted by the eye, even with the assistance of the most powerful telescope,--but a virtually unlimited number of permanent records can be made. All fields of research now feel the assistance imparted by new instruments and methods. Even the chemist realizes the aid of instruments invented by the physicist; while every physicist welcomes the aid that comes to him from chemists. The chemists and the physicist are now working together in harmony and with enthusiasm, engaged in a friendly rivalry as to which shall help the other most. And, as discovery succeeds discovery, and invention succeeds invention, they find themselves--although the domain of each is widening--not drifting farther apart, but drawing closer together. For it seems to be coming more and more assured that the Laws of Nature are simpler than we thought, that chemistry and physics are more alike than we supposed. Many startling generalizations have been suggested, with much reason; such as, that matter and energy are one, that space and time are one, and that even the mind of man may be subjected to physical methods and analysis. In fact, some of the greatest advances made during the past twenty-five years have been in psychology, and achieved largely by the use of physical apparatus. Many subjects, formerly included with alchemy and astrology in the class of occult if not deceitful arts, are now being developed apparently toward more or less exact sciences; as alchemy was developed into chemistry, and astrology into astronomy. Efforts are even being made to communicate with distant planets and with the spirits of the dead. That much is being attempted that may not be realized is true. But if we realize that the universe is now supposed to be many millions of years old, it seems only yesterday that the phenomena of electrical and magnetic attraction and repulsion were confusing the minds of even the wisest: and now electricity and magnetism are harnessed together, and working together in perfect harmony and marvelous effectiveness, for the good of man.