Reproduced with this article is a photograph of dandelion seeds —­ a magnification of nine diameters or eighty-one times.  The apparatus which produced this photograph consisted of a camera of fairly long draw, a means for holding it vertical, a short-focus lens, and, if possible, but not essential, a means for focusing that lens in a minute manner.  On top of the tripod is the folding arrangement, which is easily constructed at home with two hinged boards, an old tripod screw, an old bed plate from a camera for the screw to fit in, and two sliding brass pieces with sets crews that may be purchased from any hardware store under the name of desk sliding braces.  To the front board is attached a box, carrying the lens and the bed of the sliding object carrier, which can be moved forward and back by the rack and pinion, that also can be obtained from hardware stores.  If the bed for the object carrier be attached to the bed of the camera instead of to the front board, the object carrier need have no independent movement of its own, focusing being done by the front and

[Illustration:  Enlargement with a Camera]

back focus of the camera; but this is less satisfactory, particularly when accurate dimensions are to be determined, says the Photographic Times.  This outfit need not be confined to seeds alone, but small flowers, earth, chemicals, insects, and the thousand and one little things of daily life—­all make beautiful subjects for enlarged photographs.  These cannot be made by taking an ordinary photograph and enlarging through a lantern.  When a gelatine dry plate is magnified nine diameters, the grains of silver in the negative will be magnified also and produce a result that will not stand

[Illustration:  Magnified Nine Diameters]

close examination.  Photographs made by photomicrography can be examined like any other photographs and show no more texture than will any print.

** Steel Pen Used in Draftsman’s Ink Bottle Cork [117]

A steel pen makes an ideal substitute for a quill in the stopper of the draftsman’s ink bottle.  The advantage of this substitute is that there is always one handy to replace a broken or lost pen, while it is not so with the quill.  —­Contributed by George C. Madison, Boston, Mass.

** How to Make a Pilot Balloon [118] By E. Goddard Jorgensen

Unusual interest is being displayed in ballooning, and as it is fast becoming the favorite sport many persons would like to know how to construct a miniature balloon for making experiments.  The following table will give the size, as well as the capacity and lifting power of pilot balloons: 

Diameter.  Cap. in Cu.  Ft Lifting Power.
  5 ft. 65 4 lb.
  6 ft. 113 7 lb.
  7 ft. 179 11 lb.
  8 ft. 268 17 1b.
  9 ft. 381 24 lb. 10 ft. 523 33 lb. 11 ft. 697 44 lb. 12 ft. 905 57 lb.