In The Last Days of John Brown, Thoreau writes:
“He nothing common did or mean Upon that memorable scene, Nor called the gods with vulgar spite, To vindicate his helpless right; But bowed his comely head Down as upon a bed.” What a transit was that of his horizontal body alone, but just cut down from the gallows-tree! We read, that at such a time it passed through Philadelphia, and by Saturday night had reached New York. Thus, like a meteor it shot through the Union from the Southern regions toward the North! No such freight had the cars borne since they carried him Southward alive.
I can understand that one could describe the transport of a body as horizontal, e.g. such that is carried out by train over the surface of the earth. What is meant here be the body itself being horizontal?