Sweet is the memory of distant friends! Like the mellow rays of the departing sun, it falls tenderly, yet sadly, on the heart.
It was inevitable that in doing this I should arrive at new results, and it is perhaps understandable that in the end I have felt impelled to present these results not only in the dry form of a catalogue, but also in a more connected and personal one.
The cloud never comes from the quarter of the horizon from which we watch for it.

