DEAR MOTHER AND SISTER,--I write, now, because I must go hard at work as soon as I get to San Francisco, and then I shall have no time for other things--though truth to say I have nothing now to write which will be calculated to interest you much. We left the Sandwich Islands eight or ten days--or twelve days ago--I don't know which, I have been so hard at work until today (at least part of each day,) that the time has slipped away almost unnoticed. The first few days we came at a whooping gait being in the latitude of the “North-east trades,” but we soon ran out of them. We used them as long as they lasted-hundred of miles--and came dead straight north until exactly abreast of San Francisco precisely straight west of the city in a bee-line--but a long bee-line, as we were about two thousand miles at sea-consequently, we are not a hundred yards nearer San Francisco than you are. And here we lie becalmed on a glassy sea--we do not move an inch-we throw banana and orange peel overboard and it lies still on the water by the vessel's side. Sometimes the ocean is as dead level as the Mississippi river, and glitters glassily as if polished--but usually, of course, no matter how calm the weather is, we roll and surge over the grand ground-swell. We amuse ourselves tying pieces of tin to the ship's log and sinking them to see how far we can distinguish them under water--86 feet was the deepest we could see a small piece of tin, but a white plate would show about as far down as the steeple of Dr. Bullard's church would reach, I guess. The sea is very dark and blue here. Ever since we got becalmed--five days--I have been copying the diary of one of the young Fergusons (the two boys who starved and suffered, with thirteen others, in an open boat at sea for forty-three days, lately, after their ship, the “Hornet,” was burned on the equator.) Both these boys, and Captain Mitchell, are passengers with us. I am copying the diary to publish in Harper's Magazine, if I have time to fix it up properly when I get to San Francisco. I suppose, from present appearances,--light winds and calms,--that we shall be two or three weeks at sea, yet--and I hope so--I am in no hurry to go to work. Sunday Morning, Aug. 6. This is rather slow. We still drift, drift, drift along--at intervals a spanking breeze and then--drift again--hardly move for half a day. But I enjoy it. We have such snowy moonlight, and such gorgeous sunsets. And the ship is so easy--even in a gale she rolls very little, compared to other vessels--and in this calm we could dance on deck, if we chose. You can walk a crack, so steady is she. Very different from the Ajax. My trunk used to get loose in the stateroom and rip and tear around the place as if it had life in it, and I always had to take my clothes off in bed because I could not stand up and do it.