. Journal of applied microscopy and laboratory methods. lens)into sharpest focus. Those who do not use a rule of this kind will find it a sur-prising convenience. If the stand is of a different design it is sometimes prac-ticable to mark these distances upon the post to serve the same purpose. (2) A Ruled Card is prepared from a piece of heavy cardboard 30 x 30inches, the size of the glass plate, and ruled so as to have areas correspondingto multiples of different sized plates. Where a large number of plates are used,the cost becomes an item worth considering, and there is no occasion for usin
. Journal of applied microscopy and laboratory methods. lens)into sharpest focus. Those who do not use a rule of this kind will find it a sur-prising convenience. If the stand is of a different design it is sometimes prac-ticable to mark these distances upon the post to serve the same purpose. (2) A Ruled Card is prepared from a piece of heavy cardboard 30 x 30inches, the size of the glass plate, and ruled so as to have areas correspondingto multiples of different sized plates. Where a large number of plates are used,the cost becomes an item worth considering, and there is no occasion for usingan 8x 10 plate if G^/^ x 8j^ or .5 x7 will answer. The areas for the 4x5 and8 X 10 plates are 30 x 24, x 20, 20 x 16, 15 xl2, 10 x 8, 5 x 4, and 2i^ x 2. Thereverse side of the card is ruled for the 5x7 and 6|4 x 8^ plates. These twosizes do not coincide as is the case with the 4x5 and 8 x 10, so a dotted line isused for the 6^/^ x 8^ fields and a line for the 5 x 7. This ruled card serves two purposes : (1) The object is placed upon it to ascer-. 1204 Journal of Applied Microscopy tain what sized plate will cover it with the least waste. It also shows at a glancehow much the object will be reduced or enlarged for that particular plate, andby reading the rule the camera may be adjusted at once. (2) The card beingplaced imder the glass plate shows the exact field that the object should occupyto be included on the ground glass. (3) A Glass Plate. A method for posing insects, and one equally serviceablefor arranging flowers, is to secure a clean glass plate, such as the glass from aphotographic plate or other equally good sheet of glass of the desired size. Theobject is arranged upon this glass and when properly posed is slipped into posi-tion under the lens. The glass being clean, the plate of the stand likewise, andboth free from defects, no image of either will be formed on the sensitive method was developed by Prof. A. L. Quaintance while associated with thewri
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectmicrosc, bookyear1901
