Wagner-Fennel Sliding Tachymeter, 1907

Engraved on the lower ruler: "Otto Fennel & Söhne, Cassel, No. 7237, Representant pour la Russie G. Gerlach, Varzovie", lacquered and blackened brass, silvered scales, 6 ¾ in. horizontal circle, 2 magnifiers, 2 bubble levels, lateral rod-type compass, 3 graduated rulers, all three are arranged in a plane parallel to the plane in which the telescope turns. The inclined scale is attached to the telescope exactly parallel to its line of collimation and moves with it. The horizontal scale is fixed to the upper horizontal plate of the theodolite. The vertical scale is on the vertical edge of a right-angled triangle, which can be slid along on the top of the horizontal scale. The inclined scale carries a slider which is provided with two verniers. Length of the telescope 15 in., overall height 16 1/6 in. - A very rare instrument, in good original condition!

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)