The simple incident of the falling apple is said to have suggested to Newton the theory of gravitation. So also the discovery that the length of a letter's journey makes no appreciable difference to the cost of that journey led Rowland Hill to think of uniformity of rate; and in that portion of his “Life” which is autobiographic he said that the “discovery” that such a rate would approach nearer to absolute justice than any other that could be fixed upon was “as startling to myself as it could be to any one else, and was the basis of the plan which has made so great a change in postal affairs” (i. 250). Mention has already been made of the time-wasting and costly mode in which, during or after delivery of the letters, the postage had to be collected, necessarily in coin of the realm. In rural districts the postman's journey, when twofold, doubled the cost of its delivery, its distance, and its time-duration. The accounts, as we have seen, were most complicated, and complication is only too apt to spell mismanagement, waste, and fraud. Simplicity of arrangement was imperative. But simplicity could only be attained by getting rid of the complications. The work must be _changed_. Time must be saved, and unprofitable labour be done away with. But how? By abolishing the tiresome operations of “candling” and of making the “calculations” (of postal charge) now inscribed on every letter; by expediting the deliveries, and by other devices. Above all, the public should learn to undertake its due share of work, the share non-performance of which necessitated the complications, and swelled the expenses. That is, the _sender_ of the letter should pay for its transit before the Post Office incurred any cost in connection with it, only, as under the existing system and in numberless cases, to meet with a refusal on the part of the should-be receiver to accept it. In other words, prepayment must be made the rule. Prepayment would have the effect of “simplifying and accelerating the proceedings of the Post Office throughout the kingdom, and rendering them less liable to error and fraud. In the central Metropolitan Office there would be no letters to be taxed, no examination of those taxed by others; no accounts to be made out against the deputy postmasters for letters transmitted to them, nor against the letter-carriers. There would be no need of checks, no necessity to submit to frauds and numberless errors for want of means to prevent or correct them. In short, the whole of the financial proceedings would be reduced to a single, accurate, and satisfactory account, consisting of a single item per day, with each receiver and each deputy postmaster.”[78]