posted on Dec, 5 2007 @ 01:00 AM
Well done Mira.
Looking at the photos at the site linky I do recognize the heptagram shape and would bet the heptagram goes no more than 4 feet
into the rock, round-ish-kinda deeper than that. That's a small hole and doesn't sound deep at all.
It happens when you're punchin' a hole with compressed air and a hex bit setting up for cordite or slurry shots. It doesn't matter the angle
horizontal, down... Guys in Sudbury drill up sometimes. The drill doesn't spin "around" it reciprocates either 30 or 60 degrees and then back...
while hammering in, six sides groove out a seventh. Different machines can be set up to vary this degree of rotation and hammer stroke. Next time you
see a person running a jackhammer have a look you'll see what I mean (wear safety glasses and ear protection if you get up close).
The shape happens from harmonics and the drill bit fightin' for bite. Get a few feet in and it will round out unless they were stupid enough to use a
really bent bit. When you cut a hole with a dull or bent pike this happens. With a fresh bit and cutting fluid you get a round cut because the drill
doesn't helicopter and wobble. Certain drill and air compressor problems can produce some weird results too.
Way back about the time of the survey arc there
Struve Geodetic Arc 1828-1855
holes were drilled by hand and guess what? You can get the same shape when the bit-holding person rotates and lifts the bit while sometimes 3 to 4
people would take turns hitting the bit's strike head with 20 pound sledge hammers with a hollowed striker to prevent the top of the bit from
fragmenting and possibly killing someone. It was the 1800's people worked very hard and it was dangerous.
Nice thread. Cheers
Vic
EDIT - The Halliburton dude had the best answer.
[edit on 5-12-2007 by V Kaminski]