Popular Science Monthly
��A Photographic Trick— Try It the Night of the Fourth
THE young man in the accompanying illustration, pictured as looking so calmly and critically at us from behind one of the rings of Saturn or some other astronomical wonder, is really standing out in his own back yard, in Hornell, New York, and posing for his pho- tograph while whirling a sparkler, such as children delight in for the safe and sane Fourth of July cele- bration.
A four by five camera was used with a poly- chrome plate. The photograph was taken by the light of the sparkler, and the dark spot over the right shoulder is the which held and whirled it.
���the suitcase laboratory illustrated, with which valuable information is quickly obtained as to the purity of chemicals. This "pocket edi- tion" laboratory en- ables the laundryman to test all his materials as he buys them. Thus he is able to assure himself that everything used in his establish- ment is of a sort that will not damage or harm the goods en- trusted to him. In other words, he sub- mits all his purchases to a chemical analysis, without going to the expense of hiring a chemist to do the same thing for him.
When closed , the lab- oratory resembles a suitcase. It becomes a laboratory by raising the handle side and lowering the side which forms the lid. The lowered side forms a table.
��a photograph by the light ng sparkler which he holds
��hand
��A Suitcase Laboratory for the Use of the Laundryman
THE Mellon Institute of Industrial Research has been studying the laun- dry business scientifically. It wants to help the laundrymen guard against bad laundrv materials. The result has been
���The suitcase labor- atory which is used by laundrymen for testing the materi- als they use and the hardness of water
��A Hint to Motorists — Keep Your Radiator Clean
TO assure the efficient operation and long life of your automobile, it is essential that the radiator be kept clean. Every radiator has been designed for the purpose of dissipating some of the heat from the engine to prevent it from over- heating. The radiator can only accomplish this when the radiator cells are cleared of mud so that the comparatively cool ^^^^ air can circulate through it. Yet ^M 8L many are the cars which are
^ PPtt allowed to clog up with
mud and dirt until it al- most takes a hammer to knock it out. A good antidote is a powerful stream of water from a hose; or where this may not be convenient, a stiff brush or a broom will assist in solving the cleaning problem. Care in this respect will be repaid in good measure.
�� �
