Discoveries of the Last Half Century.
THERE has been no period since the commencement of the world, in which so many important discoveries, tending to the benefit of mankind, were made, as in the last half century. Some of the most wonderful results of human intellect have been witnessed in the last fifty years. Some of the grandest conceptions of genius have been perfected. It is remarkable how the mind of the world has run into scientific investigation, and what achievements it has effected in that short period. Before the year 1800 there was not a single steamboat in existence, and the application of steam to machinery was unknown. Fulton launched the first steamboat in 1807—now there are 3,000 steamboats traversing the waters of America, and the time saved in travel is equal to 70 per cent. The rivers of nearly every country in the world are traversed by steamboats. In 1800 there was not a single railroad in the world. In the United States alone there are now 8,797 miles of railroad, costing $286,000,000 to build, and 22,000 miles of railroad in England and America. The locomotive will now travel in as many hours, a distance which in 1800 required as many days to accomplish. In 1800 it took two weeks to convey intelligence between Philadelphia and New Orleans—now it can be accomplished in as many minutes by the electric telegraph, which only had its beginning in 1843. Voltaism was discovered in March, 1800. The electro-magnet in 1821. Electrotyping was discovered only a few years ago. Hoe's printing press, capable of printing 10,000 copies an hour, is a very recent discovery, but of a most important character. Gas light was unknown in 1800; now every city and town of any pretense are lighted with it, and we have the announcement of a still greater discovery, by which light, heat, motive power, may all be produced from water, with scarcely any cost. Daguerre communicated to the world his beautiful invention in 1839. Gun-cotton and chloroform are discoveries but a few years old. Astronomy has added a number of new planets to the solar system. Agricultural chemistry has enlarged the domain of knowledge in that important branch of scientific research, and mechanics have increased the production, and the means of accomplishing an amount of labor, which far transcends the ability of united manual efforts to accomplish. The triumphs achieved in this branch of discovery and invention are enough to mark the last half century, as that which has most contributed to augment personal comforts, enlarge the enjoyments, and augment the blessings of man. What will the next half century accomplish? We may look for still grander discoveries; for intellect of man is awake, exploring every mine of knowledge, and searching for useful information in every department of art and industry.—Phil. Ledg.