But, preternaturally acute though their senses seemed to me to be, they would rely upon their decisions no more than the modern scientist of the West would rely upon his. Error, they held, was ever maiming the conclusions from reports of the senses, and they took every precaution in recording or using their own perceptions. Accurate though their sense-memory was, they had instruments which kept a permanent record of any report of the senses they meant to use again. Not merely sounds and sights did they automatically record, but perfumes, and flavours, and electric impressions. Ages before, the inasan or recorder of light and the linasan or recorder of sound had been brought to a high pitch of perfection; all the colours and forms seen in nature, at whatever distance, could be kept in permanence on irelium-plates and reproduced to the eye by the insertion of the plates in the inasan and the reversal of the instrument. So was it with sounds, however loud or faint; the linasan would tell out to the ear music or speeches recorded hundreds of years before down to the minutest tone. By a modification of these two instruments they took record of the inner structure of things even at cosmic distances, and of sounds which seemed to be intercepted by vast material obstructions. The development of the recorders of the other senses had been more recent; not till perfumes and tastes and electricity had begun to enter largely into education and the stimulance of memory did the necessity for such instruments arise. In the earlier times before the purgation of the race these instruments would have been a temptation to new and epicurean vices. Now they were nothing if not educational aids. The farosan or aromagraph enabled the gardeners to arrange the mnemonic harmonies of flowers as mere sense-memory could never have done; it could reproduce any subtle perfume or mixture of perfumes that had ever been experienced in the island. The salosan or gustagraph gave incalculable aid to the chemical and alimentary families; without its permanencies of flavour they would have fallen into daily errors in mingling the atmospheres of the halls of sustenance and medication and those of Ilarime. By its aid they could recall any of the tastes which had made substances or compounds pleasing to the palate. But it was the idrosan or electrograph that was most needed; for the firla or electric sense had been so recently developed that its reports as to the amount and quality of any electric impulse were most untrustworthy. Without the aid of this recorder they could never have compared the electric impulses of the past with those of the present, nor could they have been so accurate in measuring the electric powers of various substances.