I have just picked up a second-hand copy of a third edition of Percival Marshall’s Flying-Machines – Past, Present & Future, as pictured above. Near as I can tell it was published around 1909-1910 and found it utterly fascinating, since every book is written in the present and tells us quite a bit about the time when it was just a newly published text and hardly anything else. What intrigued me most of all was the emphasis given to conjectures about the future. Here are the last three lines of the book:
The experience of the present development of the art of flying, and opinions expressed by aviators, seem to predict that aerial navigation will be the safest of all forms of mechanical transit. Many flights have been made after sunset, practically in the dark. Mr Cody has flown in moonlight, showing that flying machines can be used at night.
In 1909 even flying at night was only a conjecture, a possibility, an aspiration. The author was confident but could hardly be certain. It seems now, just as it was then, that as we try to look ahead, we cannot actually see very far at all. All one can say with certainty is that the future will be nothing like we can imagine it today.