Letters were sometimes written on parchment with a reed [78] dipped in ink, [79] but far more frequently on waxen tablets with the _stilus_. Wax was preferred to other material, as admitting a swifter hand and an easier erasure. When Cicero wrote, his ideas came so fast that his handwriting became illegible. His brother more than once complains of this defect. We hear of his writing three letters to Atticus in one day. Familiar missives like these were penned at any spare moment during the day's business, at the senate during a dull speech, at the forum when witnesses were being examined, at the bath, or oftener still between the courses at dinner. Thrown off in a moment while the impression that dictated them was still fresh, they bear witness to every changing mood, and lay bare the inmost soul of the writer. But, as a rule, few Romans were at the pains to write their letters with their own hand. They delegated this mechanical process to slaves. [80] It seems strange that nothing similar to our running hand should have been invented among them. Perhaps it was owing to the abundance of these humble aids to labour. From the constant use of amanuenses it often resulted that no direct evidence of authorship existed beyond the appended seal. When Antony read before the senate a private letter from Cicero, the orator replied, "What madness it is to bring forward as a witness against me a letter of which I might with perfect impunity deny the genuineness." The seal, stamped with the signet-ring, was of wax, and laid over the fastening of the thread which bound the tablets together. Hence the many ingenious devices for obliterating, softening, or imitating the impression, which are so often alluded to by orators and satirists. Many of the more important letters, such as Cicero's to Lentulus, that of Quintus to Cicero, &c. were political pamphlets, which, after they had done their work, were often published, and met with a ready sale. It is impossible to ascertain approximately the amount of copying that went on in Rome, but it was probably far less than is generally supposed. There is nothing so cramping to the inventive faculty as the existence of slave labour. How else can we account for the absence of any machinery for multiplying copies of documents, an inconvenience which, in the case of the _acta diurna_, as well as of important letters, must have been keenly felt? Even shorthand and cipher, though known, were rarely practised. Caesar, [81] however, used them; but in many points he was beyond his age. In America, where labour is refractory, mechanical substitutes for it are daily being invented. A calculating machine, and a writing machine, which not only multiplies but forms the original copy, are inventions so simple as to indicate that it was want of enterprise rather than of ingenuity which, made the Romans content with such an imperfect apparatus.