The zeta-function machine depended on measuring the moment of a collection of rotating wheels.
ζ函数机依靠对转盘的测量，
This physical quantity was to be the 'analogue' of the mathematical quantity being calculated.
这个物理量，是需要计算的数学量的模拟。
On the other hand, the binary multiplier had depended upon nothing but observations of 'on' and 'off'.
而二进制乘法机则是通过观察开和关，
It was a machine not for measuring quantities, but for organising symbols.
这个机器不进行测量，而是组织符号。
In practice, there might be both analogue and digital aspects to a machine. There was not a hard-and-fast distinction.
实际上，机器还是模拟和数字的混合，这两者没有明显的界线。
The Bombe, for instance, certainly operated on symbols, and so was essentially 'digital', but its mode of operation depended upon the accurate physical motion of the rotors, and their analogy with the enciphering Enigma.
比如说炸弹机，它当然是操作符号的，本质上是数字的，但是它同时需要依靠转盘的精确运动，来模拟谜机的加密。
Even counting on one's fingers, by definition 'digital', would have an aspect of physical analogy with the objects being counted.
甚至比如说，用手指来计数，这是数字化的概念，但同时也是对物体的物理量的一种模拟。
However, there was a practical consideration which provided the effective distinction between an analogue and a digital approach.
然而，有一个界定模拟和数字的标准，
It was the question of what happened when increased accuracy was sought.
那就是考查当提高精度的时候，会发生什么。