Air bubles, says the "Amateur Photographers" are a frequent source of misfortune to the beginner chiefly because he does not know how to control them. They are especially difficult to manage when developing the larger sizes of gaslight papers, a large air bell getting beneath the print, and by preventing the developer from flooding the whole surface, causing the image to appear unevenly. Air bubbles are, to a certain extent, prevented by immersing the printing paper in water prior to sweeping on the developer, but should the water be drawn straight from an ordinary tap, it will only add more trouble, owing to the numerous air bubles it will itself contain. Should a large bubble of air get imprisioned under the print, it is quite useless to attempt to get rid of it by dabbing the print with the finger, such procedure only risking the likelihood of marks or scratches. The photograph should be at once lifted up by one corner right ou tof the developer, so allowing the air to escape. Upon letting the print sink down into the developer again, it will be found to lie quite flat, and no risk is run to damaging the film or developing unevenly.