acid added alcohol apparatus appear arrangement artist atelier avoided background bath beautiful become called camera cause chemical chloride circumstances clean coated collodion color containing corners covered dark developer direction dish distance drawing drop easily effect employed equal exposed exposure face feet figure fixing focus frame frequently front give glass gold ground-glass hand head illumination importance inches instance iodide keep latter length lens lenses less light lines look manner method moved nature necessary negative object observed once opening operation original paper particularly person photographer picture piece placed plate portrait position poured practical prepared prints produce proper quantity recommended removed represent requires result salts sensitive shadows sheet short side silver soda solution sometimes stand sufficient surface taken toning tubes turned varnish washed whole
Page 349 - York city subscribers will be charged 20 cents per annum additional, which will prepay for postage and delivery of their numbers. In remitting by mail, a post-office order or draft, payable to the order of D. Appleton & Co., is preferable to bank-notes, as, if lost, the order or draft can be recovered without loss to the sender.
Page 150 - To the solution of starch 20 grains of a wine-yellow solution of iodine in iodide of potassium solution is added (a bit of iodine thrown into a solution of iodide of potassium, 1 : 20, will furnish this in a few seconds). This will give a blue solution of iodide of starch which will keep for about four weeks.
Page 159 - Silver readily combine when hydriodic acid or iodide of potassium is added to a solution of nitrate of silver. The iodide of silver formed is precipitated of a greenish-yellow colour: it is insoluble in water or ammonia, and decomposed when heated with potash ; when fused, it acquires a red...
Page 57 - It is based on the fact that the marginal rays of the field of view strike the lens under a larger angle than the central rays, and consequently suffer a greater refraction.
Page 3 - Screw, with which the Focus is drawn upon the largest boxes with the same facility and accuracy as upon the smaller ones, and all Holders fitted with thr new Patent Glatt Corners, (without extra charge.) Single No.
Page 222 - Support a plain beaker of 50 cc. capacity in a 100 cc. beaker by means of a triangle made of copper wire, or a piece of pasteboard in which a hole has been cut just large enough to allow the body of the small beaker to pass. Fill the smaller beaker with kerosene and the larger beaker with water. In each case the level of the liquid should be within one-half inch of the top of the beaker.
Page 55 - Hence, if the ground-glass has been placed at /', the marginal rays, which have intersected the axis at /", will form a circle of dispersion.
Page 60 - The diameter of the rays, <;, <?, which pass through the lens parallel to its axis, is of the same size as the opening of the stop B.