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��placed in the center of the ring. The object of the threads is to prevent the drop of water running around the sides of the cell.

A reservoir slide, Fig. 2, is sometimes con- venient, particularly for the examination of algae, as it provides a relatively large volume of nutritive fluid. A useful trough can be made on a 3 by llo-m. slip in the following manner: Cut a piece of fiat and parallel- sided hard rubber to the shape shown at.Z>, so as to make a trough about 1 M by ^ by 3-4- in., and cement this to the slip midway between the ends and flush with the sides. Cover this with an oblong cover glass or a piece cut from an object slide, cemented on water tight. Two small pieces of glass, E and F, should be cemented to the slip to form ledges on which a circular cover glass, Gy can rest without risk of its slipping down into the trough. A filament of growing algae, H, is shown ready for examination, having been passed up from the trough in which it was growing, and covered with the thin cover glass.

In Fig. 3 is shown another useful though very simple device. It consists merely of a 3 by 1-in. slip, around which two pieces of silk or cotton threads, / and J, are tied a short distance apart, the covered glass, K, being laid across them. This forms a shallow cell which is open to the air almost all around. The water can be renewed as it evaporates by adding a drop to the edge

���F1G.3 A slide that provides a way to renew the water by adding a drop to the edge

without disturbing either the object or the glass. The drop will be sucked up by capil- lary attraction. Areation of the water is thus facilitated.

In order to make the slide rest firmly on the stage, stick small pieces of paper, L and M, to the underside, one at each end. Several slips may be prepared, using different thick- nesses of thread. These may be numbered in accordance with the depth of the cell. The numbers should be written on one of the paper strips so that they may be read through the glass. — H. J. Gray.

��Cane Chair Seats and How to Weave Them

THERE are seven steps in the weaving of the cane for a chair bottom, or other paneled work. These are described and il- lustrated in a new book, entitled Seat Weav- ing, by L. Day Perry (Manual Arts Press). First of all, the cane must be soaked for a few

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���Layout for holes to be bored in the seat frame for holding the cane

miinutes in warm water. Cold water will do, but it takes longer to make the cane pliable. Be careful not to soak the cane too long. In- sert one end through a hole, next to a corner hole, allow- ing it to project about 3 in. below, and fasten it by driving a peg in the remaining part of the hole. Pull the entire strand through be- tween the thumb and forefinger to prevent its twisting, and run the other end down through the opposite hole, next to the corner hole. Make sure that the smooth side of the cane is out on the underside of the frame as well as on top. In doing this, the cane is pulled reasonably taut, then fastened in the latter hole with a peg to prevent its slipping back and becoming loose. Draw the cane through between the thumb and forefinger again, pull it over to the next hole, or second one from the corner, and run the end up through and across the top, parallel to the first strand, and down through the opposite hole in the other piece, or second hole from the corner, and fasten with a peg. This operation is repeated until all holes have been utilized on the two parallel rails, except those at the corners. Throughout the seven operations, the cane must be kept from twist- ing by drawing it between the thumb and forefinger. With this first step completed, all holes in the two rails opposite will be entered, with all cane running parallel and on the upper side, the cane crossing from hole to hole on the underside.

The second step is just the same as the first; the only difference is that the other two rails of the frame are used and that the

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