As promised, Schorn had set up investigations to determine the length of Charlie's natural day from studies of body chemistry and cell metabolism, but he was running into trouble. He was getting results, all right, but the results made no sense. Some tests gave a figure of twenty-four hours, which meant that Charlie could be from Earth; some gave thirty-five hours, which meant he couldn't be; and other tests came up with figures in between. Thus, if the aggregate of these results meant anything at all, it indicated that Charlie came from a score of different places all at the same time. Either it was crazy, or there was something wrong with the methods used, or there was more to the matter than they thought.

Danchekker was more successful in a different direction. From an analysis of the sizes and shapes of Charlie's blood vessels and associated muscle tissues, he produced equations describing the performance of Charlie's circulatory system. From these he then derived a set of curves that showed the proportions of body heat that would be retained and lost for any given body temperature and outside temperature. He came up with a figure for Charlie's normal body temperature from some of Schorn's figures that were not suspect and were based on the assumption that, as in the case of terrestrial mammals, the process of evolution would have led to Charlie's body regulating its temperature to such a level that the chemical reactions within its cells would proceed at their most efficient rates. By substituting this figure back into his original equations, Danchekker was able to arrive at an estimate of the outside temperature or, more precisely, the temperature of the environment in which Charlie seemed best adapted to function. Allowing for error, it came out at somewhere between two and nine degrees Celsius.

With Schorn's failure to produce a reliable indication of the length of the Lunarian day, there was still no way of assigning any absolute values to the calendar, although sufficient corroborating evidence had been forthcoming from various sources to verify beyond reasonable doubt that it was indeed a calendar. As more clues to Lunarian electrical units were found by Electronics, an alternative approach to obtaining the elusive Lunarian unit of time suggested itself. If Mathematics could untangle the equations of electrical oscillation, they should be able to manipulate the quantities involved in such a way to express the two constants denoting the dielectric permittivity and magnetic permeability of free space in Lunarian units. The ratio of these constants would yield the velocity of light, expressed in Lunarian units of distance per Lunarian units of time. The units for representing distance were understood already; therefore, those used for measuring time would be given automatically.

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