Yours, pensively, ORPHEUS C. KERR. LETTER XII. GIVING AN ABSTRACT OF A GREAT ORATOR'S FLAGGING SPEECH, AND RECORDING A DEATHLESS EXPLOIT OF THE MACKEREL BRIGADE. WASHINGTON, D.C., September 8th, 1861. The weather in the neighborhood of Chain Bridge still continues to bear hard on fat men, my boy, and the man who carries a big stomach around with him will be a person in reduced circumstances before he gets to be a colonel. The Brigadier-General of the Mackerel Brigade observed, the other day, that he had been in hot water four weeks running, and ordered me to work six hours in the trenches for not laughing at the joke; he said that old Abe had people expressly to laugh at his jokes, and had selected his Cabinet officers because they all had large mouths, and could laugh easily; he said that he was resolved to have his own jokes appreciated, and if he didn't, he'd be perditionized. It's my impression--I say it's my impression, my boy, that the general got off his best joke when he promised the Mackerel Brigade to look after their interests as though they were his brothers. He may look after them, my boy, but it's after they're out of sight. I don't say that he takes advantage of us: but I know that just after a basket of champagne was sent to the camp, directed to me, yesterday, I saw him sitting on an empty basket in his tent, trying to wind up his watch with a corkscrew. I asked him what time it was, and he said the Conzstorshun must and shall be blockade--dade--did. I told him I thought so myself, and he immediately burst into tears, and said he should never see his mother again.