Before the proliferation of computers in the 1950s, did human computers use floating-point formats for their computations?


Floating-point calculation was reportedly implemented already in the 1910s ([Wikipedia](https://en.wikipedia.org/wiki/Floating-point_arithmetic#History)), so one might assume the idea must have been in circulation way earlier than that. However, I haven't found any information how people were computing back then. Since most human computer work must have been numerical, they may have used floating-point calculations.



Did human computers use floating-point arithmetics?
In the field of hydrodynamics the first calculation by a human computer was carried out around 1920 for a [project](https://ilorentz.org/history/zuiderzee/zuiderzee.html) to transform an open sea into a closed lake, with the aim to protect Holland from flooding. The physicist Hendrik Lorentz headed a task force to calculate the effect of the dike on the tidal flow.


The human computer was the hydraulic engineer Jo Thijsse. Lorentz commented as follows on this work:



> 
> The numerical calculations were so lengthy, that we came close to the
> ultimate limit of what can be done in this way. I myself had no part
> in this. I did try once or twice to set up and work out such a
> calculation, but then it would turn out that I had made a mistake, so
> that it had to be done all over again by others.
> 
> 
> 


The hydrodynamic calculation involved quantities differing by many orders of magnitude, and so necessarily required floating point arithmetic. Here is one page from their report, showing the exponential notation.


![](https://ilorentz.org/beenakker/MO/afsluitdijk.png)
