June 11, 1997 at 1:30 PM MST

At 06:51 PM MST on 10 July, the temperature of the furnace reached 450 C after cooling through the annealing range of temperatures at a rate of less than 3 degrees per day. The furnace control system has been well-behaved and annealing has been quite peaceful. The oven pilots are bored stiff, but they remain ever vigilant --- or at least as vigilant as you can be at 2 AM. The glass is now quite rigid and relatively stress free. The tension on the Inconel bands has been reduced to a fraction of its original value since support against hydrostatic forces is no longer needed. Our job now is to cool the honeycomb blank from 450 C down to room temperature without damaging it. Even though the cooling rate will increase to about 10 degrees per day for a while, there are still two months of cooling left to go before we get to open the furnace in September. Next week we will apply the "hot flotation" pushers (counterbalanced levers) which partially float the mirror and support it to protect against changes in the shape of the hearth as the furnace cools.

LBT construction on Mt. Graham is going fairly well, we are presently pouring concrete on the telescope pier at a level 56 feet above the ground. The main concrete work on the telescope pier and the enclosure ring wall should be complete by August. Then we start erecting the steel frame of the fixed section of the enclosure. In the Project Office, we are quite busy with the bidding of the main steel pieces of the telescope structure.