IBM 610 workstation computer 3358
IBM 610 workstation computer 3359
Much of the "ease of use" improvement had nothing to do with the language or its implementation, and much to...
I came along after the 7love series but I've always been told that compilers on pre-S-360 machines were not so easy to use. First, despite the claims, supposedly the created object code wasn't as good as someone could write themselves, and this was significant on the old machines. Secondly, the compiler had to make several pbuttes over the source code and that required intermediate storage, such as several tape units or a rare disk. That tied up the machine.
I don't know the percentage of programming done on the early machines (ie 709x series) in buttembler vs. Fortran, but I suspect buttembler was the main language for the reasons above. After S-360, with its more sophisticated operating system, disk drivers, and more memory, Fortran was more widely. Also, there were more college courses in Fortran by that time.
IBM 610 workstation computer 3360
oh, and for some other random stuff ... an old version of jargon leaked onto the internet and can be...
I'm told few engineers bother with Fortran anymore. It's been replaced by (1) Excel, where entering a formula isn't much different than in Fortran only the results are instantly available, (2) CAD machines which calculate for you as go design, and (3) specific design packages for various applications which also calculate as you go. There may be more legacy business applications in Fortran still in service than engineering ones; they were written in Fortran since that's what an engineering organization had skills in at the time.