From the Rio Saur to Dos Cabesas Spring is thirty-two miles. We made this in seven hours driving time. We breakfasted at the Saur; made two camps in the distance, making our last drive for the day after we had passed Dos Cabesas spring. Camped at 12 o’clock, midnight. Made 47 miles to-day. _August 28._--Harnessed at 5.45 a. m. To-day we left the main travelled road, now in use by the troops, and by trains of supplies _en route_ to Fort Buchanan. This road turns southward before coming to the San Pedro river, crossing that stream higher up than we do. The main road is in nearly a due west course till we reach the river; then we turn northward six miles before coming to the ford. This cut-off is not so well defined as the road we had been travelling. Our route lies through Tucson, to which place there has been but little direct trade; and as this was only the second mail coach which has come over the road, we found the way by no means very clearly marked out. We did not deem it prudent to cross the San Pedro river to-night, as the recent rains had swollen it to a much higher point than usual. Camped for the night on the eastern branch of the San Pedro at 11.15 p. m. Made 42 miles to-day. _August 29._--Crossed the San Pedro as soon as it was light enough to see. About 10 o’clock this morning, as we were making our second drive for the day, I saw a party approaching us mounted on mules. Rode forward to meet them. They proved to be the mail party from San Diego, who left there 9th August with an outfit of saddle mules and pack animals. Our agent had reached San Diego with men and supplies on the 21st of July, in ample time to have started the mail of the 24th, if he could have procured animals.--(See Journal of June 20.) This mail had been twenty days in coming from San Diego to our place of meeting, forty miles east of Tucson. Our mail had been twenty days coming twice the distance. I had sent positive orders in my letters, per steamer of 20th June, to San Francisco, that the mail should be started in a coach, if possible, but that at all events it was only to be sent as far east as the Pimos villages.--(See Journal of July 24.) Mr. Birch had deemed it best in San Francisco to alter this plan, and ordered complete outfits to be sent from San Diego, to go through to San Antonio. I ordered this mail party back, to return with me to Tucson, as nothing was to be gained by their continuing on. At 8 o’clock I mounted my mule, and went on to Tucson with two men. We reached there at 2 o’clock in the morning. My purpose in hastening on in advance of the train was to lose no time, but to purchase mules at once, with which to proceed to San Diego with the through mail. I wished also, if possible, to buy some description of vehicle, in which to send the mail back to El Paso. Train camped in a drizzling rain at 11 o’clock. Made 49 miles to-day.