1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65

Dobsonian telescopes use the altaz mount because it's inexpensive and makes the scope more portable. And it's fine for manual scope use. You just can't use setting circles or use cameras with such a mount. ...Well, you CAN put a clock drive on an altaz scope, but it's very expensive unless the scope already has a builtin computer.
Dobsonian Plans (to make your own): http://members.aol.com/raycash/sidewalk.htm