The conversation made me nervous and fidgetty. It also made me remember much I preferred to let fade: the Grand Army, Sprovis, the counterfeit pesetas.... All the evil I had unwillingly abetted. If a man did nothing, literally nothing, all his life, then he might be free of culpability. Manichaeism, said Enfandin. No absolution.
My idleness, I knew very well, heightened all these feelings of degradation. Were I able to continue in the happy, cocksure way I had gone about my note-gathering and the writing of volume one, I would have neither the time nor susceptibility to be plagued by this disquiet. As it was I seemed to be able to do nothing but act as audience for what was going on in the workshop.
With childish eagerness Barbara and Ace explored HX-1’s possibilities for the next two months. They quickly learned that its range was limited to little more than a century, though this limit was subject to slight variations. When they tried to operate beyond this range the translation simply didnt take place, though the same feeling of dissolution occurred. When the light faded they were still in the present. Midbin’s venture into the hayfield had been a freak, possibly due to peculiar weather conditions at both ends of the journey. They set 1850 as a safe limit, with an undefined marginal zone further back which was not to be hazarded lest conditions change during the journey and the traveler be lost.
Why this limit existed at all was a matter of dispute between them, a dispute of which I must admit I understood little. Barbara spoke of subjective factors which seemed to mean that HX-1 worked slightly differently in the case of each person it transported; Ace of magnetic fields and power relays, which didnt mean anything to me at all. The only thing they agreed on was that the barrier was not immutable; HX-2 or 3 or 20, if they were ever built, would undoubtedly overcome it.
Nor would HX-1 work in reverse; the future remained closed, probably for similar reasons, whatever they were. Here again they disputed, Ace holding an HX could be built for this purpose, Barbara insisting that new equations would have to be worked out.
They confirmed their tentative theory that time spent in the past consumed an equal amount of time in the present; they could not return to a point a minute after departure when they had been gone for an hour. As near as I could understand, this was because duration was set in the present. In order to come back to a time-point not in correspondence with the period actually spent, another HX, or at least another set of controls, would have to be taken into the past. And then they would not work since HX-1 could not penetrate the future.
The most inconvenient circumscription was the inability of one person to visit the same past moment twice. When the attempt was made the feeling of dissolution did not occur, the light went on and off with no effect upon the would-be traveler standing beneath it. Here Barbara’s “subjective factor” was triumphant, but why, or how it worked, they did not know. Nor did they know what would happen to a traveler who attempted to overlap by being already on the spot prior to a previous visit; it was too dangerous to try.
Within these limits they roamed almost at will. Ace spent a full week in October 1896, walking as far as Philadelphia, enjoying the enthusiasm and fury of the presidential campaign. Knowing President Bryan was not only going to be elected, but would serve three terms, he found it hard indeed to obey Barbara’s stricture and not cover confident Whig bets on Major McKinley.
Though both sampled the war years they brought back nothing useful to me, no information or viewpoint I couldnt have got from any of a score of books. Lacking historians’ interests or training, their tidbits were those of curious onlookers, not probing chroniclers. It was tantalizing to know that Barbara had seen Secretary Stanton at the York depot or that Ace had overheard a farmer say casually that Southron scouts had stopped at his place the day before and they had thought neither incident worth investigating further.
I grew increasingly fretful. I held long colloquies with myself which always ended inconclusively. Why not? I asked. Surely this is the unique opportunity. Never before has it been possible for an historian to check back at will, to select a particular moment for personal scrutiny, to write of the past with the detachment of the present and the accuracy of an eyewitness knowing specifically what to look for. Why don’t you take advantage of HX-1 and see for yourself?