What if Isaac Newton's Principia, and his theories, were delayed 150 years?

Newton's Principia, with his theory of Universal Gravity, his concepts of Potential and Kinetic Energy, his Laws of Motion, was first published in 1687. Of course, it would be impossible to even conceive of the modern world, without them, at this stage. Much of modern engineering and design requires them. Automobiles, trains, airplanes, rockets and satellites couldn't be built without them. Modern building design would also be impossible without them. Nevertheless, it is, I think, much less clear what exactly people in 1687 would have done with Newton's new laws and concepts, at the time. I suppose the most obvious application would have been to ordnance, and gunnery. But, even there, I'm not sure the chemical properties of gunpowder were understood with sufficient precision to really make them particularly applicable; that is, was the chemical energy contained in a given quantity of gunpowder understood sufficiently well and precisely that the concepts of energy could really be applied to it directly, at the time? When the first edition of the Encyclopedia Britannica was published in 1773, they couldn't even conceive of how to visually, graphically represent the operation of the early steam engines -- called "fire-engines" -- being used to pump water out of coal mines. The concept of a mechanism moving so rapidly as the result of artifical motive force simply hadn't existed before this time, so the science of graphical representation had to catch up with it. So, supposing no one had been aware of Universal Gravity, Potential and Kinetic Energy, or the Laws of Motion, before 1837? What difference would it really have made? I rather suspect, not a great deal. Perhaps, having them available, resulted in people trying to think of applications for them, and, over the long term, this made such developments more likely. Or, perhaps not. This also has some relevance to Relativity Theory, which has been around for almost 120 years now. Again, practical applications of Relativity seem to be a bit thin on the ground. Many would point to GPS, but, this can be, and is done empirically. In fact, the main practical application of Relativity Theory seems to be a negative one. Since almost everyone believes it is impossible to travel faster than light these days, we are making no efforts to develop nuclear powered spacecraft to travel to any of the many earth-like planets in other solar systems we now know with near certainty do exist. So, does it, possibly, require centuries before major theoretical revolutions in Physics yield significant applications? Was this the case with Newton's theories, and is it the case with Einstein's Theory of Relativity, as well? So, might we expect some major, important practical developments from Relativity Theory, within another century, or two, perhaps?