The Glenlair letters of 1857 (see last chapter) sufficiently indicate Maxwell's mental condition in the interval between his first and second sessions at Aberdeen. His expansive sociable spirit is putting forth fresh feelers, and he has made a new beginning in his observation of man in society. But he has not yet recovered from the loss of the preceding year, and those who read between the lines cannot fail to trace here and there a touch of sadness peering from beneath the habitual buoyancy of his style.

In September of this year another loss renewed the feeling of desolation which had haunted him since his father's death. His friend Pomeroy, whom he had nursed in illness, and of whose career in India he had augured so highly, was carried off by a second attack of fever, caused by a hurried journey during the first outbreak of the Mutiny. Maxwell's letters to Mr. Litchfield show how keenly he felt this blow, and what deep thoughts on human life and destiny were once more stirred up in him.

His original work on electricity was now for a while interrupted by another laborious task, which absorbed his best energies for more than a year. The examiners for the Adam's Prize, given by St. John's College in honour of the discovery of Neptune, had set as a subject, “The Structure of Saturn's Ring.” To frame and test an hypothesis which should account for the observed phenomena was a problem of no ordinary complexity, and one to which the speculative imagination and mathematical ingenuity of Clerk Maxwell were particularly adapted.