The hay business.The matter of proper feed for cavalry horses was a constant perplexity to the Federal Government until the men had learned how to care for their mounts. During the first two years of the war two hundred and eighty-four thousand horses were furnished to the cavalry, although the maximum number of cavalrymen in the field at any time during this period did not exceed sixty thousand. The enormous number of casualties among the horses was due to many causes, among which were poor horsemanship on the part of the raw troopers mustered in at the beginning of the war, and the ignorance and gross inefficiency on the part of many officers and men as to the condition of the horses' backs and feet, care as to food and cleanliness, and the proper treatment of the many diseases to which horses on active service are subject. In such a tremendous machine as the quartermaster's department of the Army of the Potomac, containing at the beginning of the war many officers with absolutely no experience as quartermasters, there were necessarily many vexatious delays in purchasing and forwarding supplies, and many disappointments in the quality of supplies, furnished too often by scheming contractors. By the time the photograph above reproduced was taken, 1864, the business of transporting hay to the army in the field had been thoroughly systematized, as the swarming laborers in the picture attest.