Erecting Prism
Strange monoliths on the school grounds?
At my high school, I recently noticed multiple concrete monoliths which have been erected. They are in the form of rectangular prisms, about 7 feet high, and 1.5 feet by 10 feet at the base. They have no artwork on them whatsoever– they simply sit. One is positioned at the edge of the soccer pitch, diagonal to the rest of the field. Two more are located on the practice football field, aligned next to each other. WHAT ARE THEY???
I would inspect the top surfaces to see if there are traces of fasteners there (bolt holes, cut off steel projections, etc.) This sort of thing would imply that they were piers or supports for some suspended structure, that has since been removed.
–
Regards,
John Popelish
60mm Telescope Meade ETX-60AT Autostar
|
|
Meade 07210 45 Degree Erecting Prism #932 $42.95 Use the Meade 932 Erecting Prism for ETX-90 & 125AT to correct images to your satisfaction. With ETX-90AT and ETX-125AT Astro Telescopes, images are reversed left to right, which isn’t desirable for terrestrial viewing. You want telescope accessories like the Meade #932 erecting prism, which delivers a fully corrected image with a 45-degree observing angle. This hardly matters for astronomical vi… |
|
|
Meade #918A 1.25-Inch Diagonal Prism $36.94 Meade #918A Diagonal Prism (1.25″) 07202… |
|
|
Orion 1.25 45-degree Correct Image Prism Telescope Diagonal $49.99 For terrestrial viewing with a refractor or Cassegrain telescope, use of a correct-image (or image erecting) prism diagonal may be desirable. The image through the eyepiece image will appear upright and nonreversed, matching the naked-eye orientation. So a correct-image diagonal is essential for terrestrial viewing with the above telescope types and is useful for astronomical viewing for those tha… |
|
|
Celestron 1.25 90° Erecting Diagonal for Telescope $29.99 This Celestron 1.25″ erect image diagonal uses an Amici prism design. This design allows you to look into the telescope at a 90° angle, at images that are oriented properly, meaning the image is upright and correct from left to right. Comes with a set of duct caps that are not shown in the photo. Has metal barrel with a plastic housing. Diagonal was part of an accessory kit that came with a C… |
|
|
New 1200X90mm Maksutov-CassegrainTelescope $399.99 … |
|
|
New 130mm Maksutov-Cassegrain Telescope $1,499.99 With tube length of 21 inches, a 130mm (5″) precision-polished fully multi-coated meniscus front lens, and solid uncompromising construction. the 130mm Maksutov-Cassegrain is a paragon of portability, optical excellence, and durability. Better still, it’s one of the most versatile scopes we offer. The model 2000×130 delivers bright, high-contrast images, and with a focal length of 2000mm (f/15.4)… |
|
|
Bushnell 1.25 Erecting Prism 780103 $64.94 Bushnell 1.25″ Erecting Prism 780103… |
|
|
Meade B120107 24×50 TravelView Full-Size Zoom Porro Prism Binoculars (Black) $89.00 The TravelView Series of binoculars is designed for those who love to travel, observe nature view sporting events, or just to enjoy the outdoors. TravelView binoculars feature Meade’s legendary optical technology and design. All TravelView binoculars feature fully coated lenses for clear, bright viewing, rubber coating for durability and come in a full range of magnifications and sizes…. |