Page:Popular Science Monthly Volume 91.djvu/370

 354

��Popular Science Monthly

���The bottles contain inks of different colors. Each pen acts as a guard for its bottle

��Don't Drench a Plant: Water It Drop by Drop

LUCIEN [DANIEL, a French botanist, j has discovered that young hothouse plants and slips of vegetables, as well as flowers, thrive far better by a system of continuous watering than by drenching the soil at stated periods. The new method depends upon the law of capillary attrac- tion. Near each plant is placed a jar con- taining water, into which is dipped one end of a strip of linen or cotton, whose other end lies near the plant. With this uninterrupted supply of water, drop by drop, the plants thrived, greatly outdistan- cing other plants, which were submitted to an intermittent drenching.

��Using a Dozen Different Inks With- out Making a Mistake

MECHANICAL draftsmen, architects and map makers often use as mani- as ten inks of different colors in making a complicated drawing. Sometimes it hap- pens that the engrossed artist thrusts his pen into the wrong bottle of ink and draws a blue instead of a red line. Then follows an effort to erase the wrong line, with consequent loss of time.

Frank B. Gilbreth, the well-known effi- ciency engineer, overcomes this difficulty very simply and ef- fectively. He has devised a special stand, to hold both the ink bottles and their pens. As the accom- panying photograph shows, each pen is thrust vertically into a hole directly in front of its bottle. The pens thus con- stitute a barrier in front of the bottles.

When a green line is to be drawn, the draftsman picks up the proper pen and thus clears the way for the green-ink bot- tle; only that bot- tle and no other can be reached. It is impossible to thrust the pen into the red-ink bottle, be- cause that is guarded

��The Sailors and Marines Sleep On Their Life-Preservers

���IT MUST afford considerable consolation to the Navy recruit to realize that the mattress on which he sleeps so comfortably at night will stand him in good stead in case of an accident to the ship. In fact the very buoyancy which makes it such a comfortable bed is also the quality which makes it possible for it to be converted at a moment's notice into a life- preserver.

The mattresses are stuffed with kapok, a light- er-than-cork material which is imported from the West Indies in bales similar to bales of cot- ton. It is made from the seeds and silk of a tree not unlike the cotton-wood tree, but instead of being in puffy balls, the kapok is in slender threads, which when compressed make a mass that is six times more buoyant than cork.

Thin layers of the kapok are enclosed in strong ticking for the mattresses. Each mat- tress is provided with tapes long enough to tie around the body and over the shoulders, as shown in the illustration. It requires only a minute

��by its pen.

��tion in their life-preserver mattresses to adjust them.

�� �