Photoscope Viewer, post-1871

G & C. (attributed to Gasc & Charconet Opticiens, 10 Rue de Malte Paris), movable viewer on brass stand for high magnification and a number of applications, embossed on the front: "G & C. Brevete S.G.D.G. K.K. Privilegium Patent", with instruction label on the tube, small dent in top, with wood case. – Note: Designed for projecting 7 mm diameter transparent slides, this viewer is also ideal for use with Dagron carrier pigeon dispatches on collodion, as a converging lens (condenser) in front of the 67 x 36 mm slide, as a focusable micro-lens with fixed aperture-stop behind the slide, for viewing on the 147 mm ground optics screen with a strong light source and for microscopic preparations. An excellent exhibit on the history of communications technology and photography.

布雷克拍品等级是为了方便竞买人判断拍卖品的成色而设置的。布雷克等级用1到6级来标注外观和功能的成色，(从非常好到非常差)。 在目录图册里用括号里的2个数字来表示，前一个数字表示外观成色的级别，后一个数字表示功能成色的级别。如(3/2)表示外观成色是3(满意的)，功能成色2(好)。 成色 定义参照下列标准： 1 - 非常好 (未使用过，没有使用痕迹) 2 - 好 (新，极少的使用痕迹) 3 - 满意的 (普通的使用痕迹) 4 - 及格的 (明显的使用痕迹，某个非主要部件是后配的) 5 - 有缺陷的 (极明显的使用痕迹, 某个主要部件是后配的，功能上有缺陷，需要修理) 6 - 非常差 (严重破损, 缺少重要部件)