By Stephen F Tonkin
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Within the small coastal city of Oyster Bay, North Carolina, you will find lots of characters, ne'er-do-wells, and even a number of celebs attempting to duck the paparazzi. but if homicide joins this curious neighborhood, the Bayside publication Writers are there to get the tale. .. Olivia Limoges is the topic of continuing gossip.
It began with the yankee Library organization (ALA) which desired to rejoice its centenary in 1976 at its headquarters in Chicago. With 5 American librarians and non-librarians i used to be invited to provide a centennial paper. I declined the flattering provide simply because I had left the career and had no time to do any study.
Incredible Mazes: 50 artistic Puzzles with suggestions (Dover novelty books & renowned recreations)
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Fortunately, this is a problem that has an easy fix: a longer tube. 4). You can determine how long this needs to be by putting your eye up to the racked-in focuser (without an eyepiece in place) and looking past the secondary, out of the top of the tube. With a ruler held against the tube opposite the focuser, you can see how long the extension will need to be. 4 The removable tube extension Building a High-Contrast Planetary Newtonian The Payoff So does the view justify the effort? Absolutely.
I had a section of plastic pipe that almost fitted over the soil pipe, so I cut a ring from this and split it to make a sliding collar that could butt up to the flange on the pipe. Three L-shaped aluminium struts secure the collar to a flange on the lens cell. A nut and bolt tighten the collar onto the tube via two small pieces of aluminium angle, one of which is secured to each end of the collar. An "own brand" baked-bean tin from the local supermarket was an excellent fit in the small end of the pan reducer.
If I didn't like the figure as it was emerging, I would simply go back a few steps to a sphere and begin again. Unlike shorter focal length mirrors that allow for correction on the fly, a long-focus mirror's figure appears so rapidly that there is almost no chance for alteration once it becomes evident. If one zone's correction lags behind the others, the chances are that overcorrection will occur in another part of the mirror before the original zone is brought into line. In my quest for optical perfection, I made close to a dozen parabolising attempts before achieving the final figure.
Amateur telescope making by Stephen F Tonkin