Once the location of the Observatory had been determined, the first task was to dig the hole which would ultimately support the telescope and pier. The hole was made 20 inches in diameter to accommodate the pier and 4 1/2 feet deep to insure we were below our Wisconsin frost line. The job was completed in a morning.
The next step was to determine the shape and demtions of the Observatory base. An octagon shape was chosen, with an interior working space of 10 feet. Although spacious by amateur standards, I wouldn’t want it any smaller. Once determined, the footprint was marked, unwanted turf removed, and the area leveled. Mickey, my wife worked side by side with me throughout the project.
Concrete needed for the pier base and the support posts was mixed by hand from 60 pound bags of concrete mix. I constructed a wood form to contain the top of the concrete base being poured and added conduit for latter electrical hookup. An Pier was purchased from leSueur Mfg. Co. The assembled mounting bolt kit is visible in the left corner of the image.
Care was taken to level the base and alighn the mounting bolts with true North. Running North and South, the snap line shown in the image was carefully set on a clear night with the North Star as the reference point.
Mason line was used to determine the position of the posts which would ultimately define the building structure and support its weight.
twelve 4X4 posts were set in concrete. Eight were placed to establish the octagon shape of the Observatory. The other 4 were set around the pier base to insure a solid deck floor. Treated lumber was used throughout this phase of construction.
The base of the Observatory was completed by using 2X8 and 2X6 boards for beams and josts. Weed barrier cloth and gravel were added to prevent unwanted weed growth and insect activity.
The Observatory floor was completed by securing 1/4 inch exterior plywood over deck boards. The plywood was then heavily treated with deck seal to prevent moisture damage. Care was taken to keep the floor and pier base seperate, insuring no traffic vibration within the Observatory would get transferred to the telescope.