2 Brass Microscopes

1) Society of Arts type microscope, unsigned, c. 1870, original lacquered and black-japanned brass, tilting stand, plano-concave mirror, substage diaphragm wheel with four stops, rack-and-pinion coarse focusing (defective), nosepiece micrometer knob fine focusing, mechanical stage with Alfred White-type "joystick" lever adjustment, height 13 in., with one objective lens by R.J. Beck and one eyepiece in mahogany case. – Note: The design for this English bar-limb microscope dates to a prize that was offered by the Royal Society for the Encouragement of Arts, Manufactures & Commerce, for a compound microscope that would sell for 3 guineas only and was awarded to the firm of Robert Field & Son of Birmingham. Because of the popularity, it was copied by many of the instrument builders of the time. – And: 2) Signed on the base "S. Maw. Son & Thompson, London", c. 1880, polished brass, concave mirror, substage diaphragm wheel with three stops, tilting stand, rack-and-pinion coarse focusing, nosepiece micrometer knob fine focusing, mechanical stage, one eyepiece, one objective lens, height 13 in., with live box and forceps in mahogany case, lower section with drawer for specimen slides.

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)