Purposefully fudged schematics

That's often been conjectured, but, as usual, reality is somewhat more complicated. Most other craftsmen probably couldn't have produced what he designed. Along the way, he invented new techniques of fabrication and management as well as computation. However, he probably could have built it. He did build a small version that operated as he intended. And part of the reason for the construction project at the Science Museum was to determine if the materials and tools of the time could have built the machine. In the end, much of the reason he never built a full version of his designs was that he was too much the stereotypical engineer. Almost nobody except Ada could get along with him and he made a number of enemies among those who would fund his work. The money situation led to a dispute with his primary craftsman who walked out with all the custom tools they had made. Then as he was considering his options, he realized that he could improve his design many fold and so dropped his efforts on the difference engine in favor of the analytical engine. Even with that machine, he kept stopping his efforts to realize it because he was sure that he could build his new design faster than he could finish the work he had started on the previous version. As I recall, there were over 40 different designs for the analytical engine by the time it was done, and he had never built a full version of any of them. After his death, his son did assemble a small version of one of the designs for the mill including some parts that Babbage had already fabricated before his death. There's no question Babbage was ahead of his time in many ways. But he was also understood the materials and tools well enough to design a machine that he felt confident he could actually build. BLS