diagraph 的词源

“一种可以绘制物体而无需艺术技巧的工具”，1847年；参见 dia- + -graph。

It consists of a carriage for a pencil governed by a system of cords and pulleys working at right angles to one another, and set in motion by the movement of a pointer, which is passed by the operator, who is careful to keep his eye at a fixed point of view, around the apparent outlines of his subject. The pencil describes on the paper the exact motions of the pointer, and thus reproduces the desired object. [Century Dictionary]

它由一个铅笔架构成，这个铅笔架通过一套在相互垂直方向上工作的绳索和滑轮系统来控制，并由一个指针的运动驱动。操作员会小心地将视线固定在一个点上，沿着他所描绘对象的轮廓移动指针。铅笔在纸上描绘出指针的精确运动，从而再现出所需的对象。[世纪词典]

早期它的意思是“描述”（1798年起）。