Page:Popular Science Monthly Volume 91.djvu/904

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��Popular Science Monthly

��A Novel Color Mixer for Teaching Blending Effects

AVERY simple and novel device for illustrating the various color effects produced by mixing different paint pig- ments can be made in the follow- ing way :

Prepare a series of pigment "matches," as shown in the illus- tration. This can be done by obtaining the soluble pigments in dif- ferent colors and making each into a thick paste by mixing with a little glue. Dip the end of a match stick into the pigment and when the adhering mixture dries, mount it on a card- board with one or two other similarly prepared "matches." When these are immersed in a cylinder of water, the pigments at once dis- solve, and as they inter- mingle, the true color effects of the mixed pig- ments are at once ap- parent. This is by far the best method yet employed for teaching color effects to a class of pupils.

��Yellow dipped match

��lever.

��RecTatpped

' :n

���Pigment "matches" dissolved in water to show the effects of blending different colors

��Employing Deadly Gases Against the Sleeping Sickness Fly

N British East Africa great annoyance

��Shoe- Shining by Electricity in a Self-Elevating Chair

ANEW shoe-shining machine, invented by Otis R. Hasty, of Elgin, 111., is a combination of an ordinary chair and an electric elevator. You mount the chair at practically the normal height. The bootblack throws a An electric motor drives some gearing which raises a rack-pinion con- stituting the supporting column of the chair. The foot rest is rigidly connected with this col- umn, so that it rises at the same time.

After rubbing on the paste, the bootblack plugs a short flexible cable to a shaft jutting out at the bottom of the machine. The shaft which is geared to the motor also, imparts its rotation to the flexible cable and to the cir- cular buffer at the «;nd of the cable. The buf- fer speeds around and brushes your shoes in a twinkling. Such little time is required for the operation that one bootblack can attend to two patrons at a time, polishing the shoes of the first while the paste on the second pair is "setting."

��I

��species closely allied to the ordinary house-fly, but which in that locality is considered particularly dangerous to health. In New Langenburg, a district recently acquired from the Germans, it has been impossible to maintain horses, cows or cattle of any description on account of the mor- tality caused by the diseases which the flies are said to carry.

The extermination of the flies has therefore become a matter for Govern- mental consideration. The latest suggestion awaiting experiment is the use of gases, poisonous to the flies. These, it is believed, could be carried across the fly-infested areas by the monsoons, in the same manner as the destructive gases are carried in trench warfare.

���You don't have to be an athlete to climb into this chair. An electric motor raises you to the proper height

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