Collection of Physical Demonstration Models and Technical Device

1) Carbon arc lamp, demonstration model by John Browning, London, original lacquered brass, 2 graphite electrodes, one height-adjustable, on wood base, height 14 in. - 2) Diabetometer, marked "Diabétromètre Yvon-Dubosq à Penombres, Paris", historical blood glucose meter, original lacquered brass, length 18 ½ in., in walnut case. - 3) Magdeburg hemispheres, after Otto von Guericke, for demonstrating the effect of air pressure, brass, one bowl with valve. - 4) Circle stencils, D.FC. Fitzgerald, approx. 100 beechwood stencils of various sizes, for architects, in mahogany case. - 5) Gear model, 6 brass gears, engraved "Geo. L. Dickson Inv. 1852 - Lincoln - W. Thomas fecit 1854", hand-turned, walnut frame, height 21 2/3 in. - 6) Early hand blower, brass, with crank. - 7) 2 stereo viewers, France. - 8) Geologist's compass, Tavernier-Gravet, Paris, mahogany case, bearing by prism, instructions stamped on brass plate, screw-head for taking measurements. - And: 9) 3 further measuring instruments and a spring motor.

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)