Yet the Patent Office, while it exhibits the results of American invention, fails to show anything like the total amount of useful discovery which has been achieved on this continent since the foundation of the government. There are those who discover and invent, and who do not patent. There are discoveries which cannot be circumscribed by the filling-out of blank forms, and an official restriction on their use. This is emphatically the case with discoveries in the exact sciences, which, while they have added immeasurably to the knowledge of mankind, have also attained results the most useful and practical. [Sidenote: Meteorological Laws.] Illustrations of this truth may be found in the progress made by such sciences as astronomy and meteorology. No one can doubt the value of the result which accrues to human lore from a more accurate knowledge of astronomy, of the mutual influences of the solar system, and the physical character of its members. Nor can we deny that the rapid strides which have been made within thirty years in the science of meteorology are of the most immediate benefit to the material interests of men. The simple statement that the predictions of "Old Probabilities" as to the weather prove, in a large majority of instances, to be justified by the event,--founded as they are, not upon mere guesswork, but upon ascertained meteorological laws and a proved uniformity in the direction of storms,--is enough to show the importance of the recent discoveries in this field. One has only to reflect upon the changes in the course of little and of great events wrought by the weather, to be convinced of their large and permanent value. [Sidenote: Improvements in Machines and Methods.] We can look in no direction, however, without at once in some degree appreciating, and being astonished at, the metamorphosis which has been effected by the activity of scientific invention and discovery of the most palpably practical kind. No practical profession, trade, or industry can be named in which the improvements in machinery and methods have not been such, within the century, as to alter most of its conditions, and very greatly to multiply its efficiency and productiveness. These improvements have descended, too, from general systems to the minutest details. Cloth fabrics are not only manufactured on a very different scale and extent, but every little appliance of the machinery has been made better, and does its appointed work faster and with greater precision. [Sidenote: Steam and Electricity.] [Sidenote: Conveyances.]