ee5391aa@hydra.unm.edu (Duke McMullan n5gax) (03/11/89)
In article <37061@bbn.COM> aboulanger@bbn.com writes: >Ah the good ole days! There was indeed a book of some of the 50s-60s >Amateur Science articles including the seismometer. Wasn't the guy Gil >Strang? The publisher was Freedman. > >Albert Boulanger C. L. Stong. Yep, I enjoy Jearl Walker's "Amateur Scientist," but I sure miss Stong's. The latter had a lot more construction-oriented stuff. There was a book published containing many of the better projects -- there were a couple of copies in my high-school library, and I had one or the other checked out a LOT of the time. It seems to me that I remember reading somewhere that a more recent edition had been put out that contained more recent stuff, too, but that's lost in the mists of memory. Brother, some of those projects! The aforementioned seismometer, a linear par- ticle accelerator, vaccuum systems, cryogenics, nuclear magnetic resonance, x-ray generators, telescopes, spectrometers,... Hey, and remember, this was prior to 1965 with NO MICROCOMPUTERS AVAILABLE! "Those were The Days," d "Nous sommes les petits lapins -- assis sur nos petits derrieres." Duke McMullan n5gax nss13429r phon505-255-4642 ee5391aa@hydra.unm.edu
paul@hpldola.HP.COM (Paul Bame) (03/21/89)
Gateway Electronics in San Jose had some used seismic sensors. I got one but haven't had time to play with it. I think it's a heavy metal shell with a moving coil inside - kinda like a speaker. There is a threaded fitting (about 3/8") on one end. The whole thing is about 1.5" in diameter by 2.5" long. I suspect they are removed from military surplus something or other. You get a copy of a little op-amp circuit with it which includes, among other things, a comparator to switch an output if the detected seismic amplitude is above a certain level. Maybe these were used in land-mines :-) -Paul Bame