His projected zeta-function machine would have well illustrated the point.
图灵设计的ζ函数机，可以很好地表明这一点。
It was designed to calculate the zeta-function to within a certain accuracy of measurement.
它可以在一定的精度范围内计算ζ函数。
If he had then found that this accuracy was insufficient for his purpose of investigating the Riemann Hypothesis, and needed another decimal place, then it would have meant a complete reengineering of the physical equipment—with much larger gear-wheels, or a much more delicate balance.
如果他觉得这种精度不足以供他研究黎曼猜想，他需要更高的精度，那就需要彻底改造物理设备——用更大的齿轮，或者更精确的平衡。
Every successive increase in accuracy would demand new equipment.
要想提高精度，必须要更换新的设备。
In contrast, if the values of the zeta-function were found by 'digital' methods—by pencil and paper and desk calculators—then an increase in accuracy might well entail a hundred times more work, but would not need any more physical apparatus.
相反地，如果ζ函数机是基于数字方法，比如纸、笔和台式计算器，那么如果要提高精度，就需要增加也许几百倍的工作量，但却不需要改变物理设备。
This limitation in physical accuracy was the problem with the pre-war 'differential analysers', which existed to set up analogies (in terms of electrical amplitudes) for certain systems of differential equations.
战前的差分机，就面临着物理精度的问题。
It was this question which set up the great divide between 'analogue' and 'digital'.
通过这一点，可以明显地区分模拟方法和数字方法。
Alan was naturally drawn towards the 'digital' machine, because the Turing machines of Computable Numbers were precisely the abstract versions of such machines.
艾伦显然对数字机器更感兴趣，因为《可计算数》中的图灵机，就是一个假想的数字机。
His predisposition would have been reinforced by long experience with 'digital' problems in cryptanalysis—problems of which those working on numerical questions would be entirely ignorant, by virtue of the secrecy surrounding them.
艾伦有那么长的一段经历，都在研究密码分析中的数字问题，这也加重了他对数字机的倾向。
He was certainly not ignorant of analogue approaches to problem-solving.
但他也并没有无视模拟方法，
Apart from the zeta-function machine, the Delilah had an important 'analogue' aspect.
除了ζ函数机之外，黛丽拉机也具有模拟机的特点，
It depended crucially on accurate measurement and transmission of the amplitudes, in contrast to the X-system, which made them 'digital'.
它依赖于对振幅的精确测量和发送，这使它与X系统有着本质的区别。