One reason that religions in particular might have to fear air pumps and electrical machines could be a situation in the first few pages, around page 119 through the next few pages, where Johnson talks about how the extremely large plants and “the puzzle of the Meganeura” were in fact a truth and no longer a mystery because they found proof of life before man and its effects on Earth utilizing aspects of Priestly’s work to do so (Johnson pg. 119). This threatens religious views of the origin of man being Adam and Eve and the world not being created in only seven days, etc. A reason governments could have to fear these things could be that “every important kind of revolution needs both kinds of minds to complete itself” (Johnson pg. 230). As told in this book, Priestly rose to prominence through his work with air pumps and electrical machines, and with this rise to prominence gained influence in the community. This all lead to his opinions meaning more about both good and bad things and led to such things as the Riots in Birmingham. Air pumps and electrical machines lead to advancements in life and dangerous new waters for religions and governments.
Johnson’s work shed new light on the era of gigantism, where basically everything on Earth was bigger sometimes by tens of feet and how that situation is in fact due to the large growth of plants that provided an excessive amount of oxygen, around 30% of Earth’s atmosphere back then, now settled around 20%. This is a piece of scientific research that could hold political consequences in that the homeostasis of Earth is delicate and should be maintained at all costs which plays into the political arena of global warming and whether it’s true (it is), or not and how that affects the world and humans.
I think you’re right when you say religion and governments should be scared of air pumps and electrical machines because they can help prove the world was not designed specifically for humans. This type of scientific research began to open to flood gates to a kind of thinking that aloud scientists to begin to question everything about religion. I think this kind of scientific research pours into almost every kind of modern-day science we see all around us today. Religion and governments should be even more scared today than they were in Priestly’s time. Scientific research is only getting more and more accurate, proving more and more things false, that we once thought true about religion.