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Dear Alex: my bum vision kept me from appreciating some of the features of that lash-up. And the artist failed to have some proportions optimum. If started with ropes hitched by those snap-hooks in optimum position, the barrel could be rolled pi times diameter, which could equat the height of the plank that is the ramp. If slippage were not a problem, the barrel could climb far enough to tilt the plank to lie horizontally. The axis of the barrel would rise only about equal to diameter, so the mechanical advantage would be about pi, or three times, better than I thought at first.
So for such a short lift, the apparatus would work. But the ramp length could not be greater than pi times d.
Thanks for the fun of thinking about it.
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so how does parbuckle relate to turnbuckle? I mean, etymologically-like? 
formerly known as etaoin...
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Dear etaoin: I had to look it up. The first example I found was an arrangement to adjust throw of a railroad switch by means of a rod threaded at both ends, coupled at one end to the movable portion of the track, and the other to the switch, making it possible to adjust the length of the rod connecting the two devices.
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right, Bill. I have turnbuckles on my screen door, attached to long rods on the diagonal to adjust the squareness of the door. I'm wondering how the two words, parbuckle and turnbuckle, relate, word-wise.
formerly known as etaoin...
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Dear etaoin: I suddenly remembered the turnbuckles on my screen doors, and almost choked on the pie I was eating. Detail about them, an elongated "O" has threaded holes aligned with axix,at each end, but the rod ends have to have one end thread right handed,and other end left hand threaded to get change in length. I also used miniature ones in my radio controlled airplanes, to adjust some of the controls. The essential part of the parbuckle is the snaphook used to hitch the chain around the barrel Here are some pictures of various kinds:(not as strong as the ones in the picture) http://anyardfactory.com/lanyard-hardware-option.htm
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Thanks for telling us, dnes; I hate knowing there's something out there that I just can't find!
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I did some more searching for parbuckle, and found many sites that mentioned it, so that it is clear it is a fairly common term in mechanical engineering. I even found it used in a site about Paul Bunyan!
"The Winter of the Deep Snow everything was buried. Paul had to dig down to find the tops of the tallest White Pines. He had the snow dug away around them and lowered his sawyers down to the base of the trees. When the tree was cut off he hauled it to the surface with a long parbuckle chain to which Babe, mounted on snowshoes, was hitched."
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AHD says Alteration (influenced by BUCKLE) of parbunkel.] . I couldn't find any etymology listed for turnbuckle, but given the def. I have to say I think it's pretty obvious. I decided to try looking up par, when it's used as a prefix, since buckle has a clear meaning here. Two dictionaries directed me to LU para-. This is from infoplease:
para-
1. a prefix appearing in loanwords from Greek, most often attached to verbs and verbal derivatives, with the meanings “at or to one side of, beside, side by side” (parabola; paragraph; parallel; paralysis), “beyond, past, by” (paradox; paragogue); by extension from these senses, this prefix came to designate objects or activities auxiliary to or derivative of that denoted by the base word (parody; paronomasia), and hence abnormal or defective (paranoia), a sense now common in modern scientific coinages (parageusia; paralexia). As an English prefix, para- 1 may have any of these senses; it is also productive in the naming of occupational roles considered ancillary or subsidiary to roles requiring more training, or of a higher status, on such models as paramedical and paraprofessional: paralegal; paralibrarian; parapolice.
2. Chem.a combining form designating the para (1, 4) position in the benzene ring. Abbr.: p-. Cf. meta- (def. 2c), ortho- (def. 2b). See diag. under ortho-. Also, esp. before a vowel,par-. http://www.infoplease.com/ipd/A0577416.html
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formerly known as etaoin...
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Um... or Fatty?
who said "bunkel"??
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