The great variety of female ability could be observed especially well at the World’s Fair in Chicago, in 1893. The splendid woman’s building had been entirely planned by female architects, and the articles displayed that had been designed and made by women exclusively, were much admired for their tasty and artistic execution. In the realm of invention, too, women have achieved much and will achieve still more. An American trade-journal published a list of inventions by women; among them were: An improved spinning machine; a rotary loom, which produces three times as much as the usual kind; a chain elevator; a connecting-rod for a propeller; a fire-escape; an apparatus for weighing wool, one of the most delicate machines that have ever been invented, of immeasurable value to the wool industry; a fire extinguisher; a process of employing petroleum as a fuel for steam-engines instead of wood or coal; an improved spark-catcher for locomotives; a signal for grade-crossings; a system of heating cars without fire; a lubricating felt to diminish friction (on railroads); a typewriter; a signal-rocket for the navy; a deep-sea telescope; a system for subduing the noise of the elevated trains; a smoke-consumer; a machine for folding paper bags, etc. Many improvements on sewing machines have been made by women; for instance, an appliance for sewing canvas and coarse cloth; an apparatus for threading the needle while the machine is running; an improvement of machines for sewing leather, etc. The last-named invention was made by a woman who was a harness-maker in New York. The deep-sea telescope, invented by Mrs. Mather and improved by her daughter, is an invention of great importance, since it makes it possible to examine the keel of the largest vessel without bringing same into a dry-dock. With the aid of this telescope sunken wrecks may be examined from ship-board, obstacles to navigation and torpedoes may be located, and so forth. A machine famed in America and Europe for its complicated and ingenious construction, is one for the manufacture of paper bags. Many men, among them noted mechanicians, had tried in vain to construct a machine of this sort. It was invented by a woman, Miss Maggie Knight. The same lady has since invented a machine for the folding of paper bags, which performs the labor of thirty persons. She personally conducted the construction of this machine in Amherst, Massachusetts. [167] A statistic compiled by Blaschko gives the following information in regard to the extension of sexual diseases among the various occupations. First come the secret prostitutes with 30 per cent; then the students with ~25~ per cent; merchants with 16, and workingmen with 9 per cent. [168] In special cases women may be excluded from certain lectures with the consent of the minister of education. [169] The organization of free clinical treatment of patients in the large cities of Russia.--German Quarterly of Public Hygiene.