On May 1, 2014, at 12:16 AM, Mark H Harris <harrismh...@gmail.com> wrote:
> On 4/30/14 10:56 PM, Paul Rubin wrote: > >> There is a nice Javascript simulation of the N4-ES here: >> >> http://www.antiquark.com/sliderule/sim/n4es/virtual-n4es.html >> > > Thank you! > > The N4-ES and the N4-T (mine) are essentially the same rule. The N4-ES on the > site is yellow (mine is white) and the site rule indicates Picket & Eckel > Inc. (that's where the E comes from) Also the the ES states Chicage Ill USA > where the T states Made in USA. > I’ve resisted - but finally have to jump into this discussion... Picket used to talk a lot about their yellow background being optimized for the color the human eye was most sensitive to and therefore produced the sharpest focus and allowed the most precise reading of the scales. Nice theory, but at least on MY Picket rule the scales were printed not engraved and the result negated any possible advantage the color might have given. I’m surprised no one has jumped in to defend/tout the Dietzgen slide rules (which I always thought were the ultimate). Mine (their Vector Log Log) is one of their Microglide series that had teflon rails inserted in the body and is still totally stick-free after nearly 50 years. Taking it one step further, I _ALSO_ have a Curta Type II calculator http://en.wikipedia.org/wiki/Curta_calculator - which still operates as smoothly as it did the day I bought it. -Bill > The only technical difference is the T scale (which is folded-expanded on > both). On the ES the T scale is listed only once in the margin. On the N4-T > the T scale is listed 'twice'!-- once for each part of the fold. Well, that > gives (2) scales instead of one --for T... increasing the number of scales > on the rule from 34 to 35... if I'm counting right. Which makes the N4-T > more valuable... supposedly. I don't plan are parting with it... till I > croak, then my son (who is studying engineering this fall) will inherit it... > heh he won't have a clue what to do with it ! > > The simulated rule on the site above is fabulous... especially if viewed from > a large wide LED. ... simply fabulouso/ :) > > > > marcus > -- > https://mail.python.org/mailman/listinfo/python-list -- https://mail.python.org/mailman/listinfo/python-list
