From owner-freebsd-chat@FreeBSD.ORG Tue May 20 14:44:15 2008 Return-Path: Delivered-To: chat@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 730141065671 for ; Tue, 20 May 2008 14:44:15 +0000 (UTC) (envelope-from john@brann.org) Received: from mta4.srv.hcvlny.cv.net (mta4.srv.hcvlny.cv.net [167.206.4.199]) by mx1.freebsd.org (Postfix) with ESMTP id 4334D8FC13 for ; Tue, 20 May 2008 14:44:15 +0000 (UTC) (envelope-from john@brann.org) Received: from freebie.brann.org (ool-45768fe8.dyn.optonline.net [69.118.143.232]) by mta4.srv.hcvlny.cv.net (Sun Java System Messaging Server 6.2-8.04 (built Feb 28 2007)) with ESMTP id <0K160062P7JBDSN0@mta4.srv.hcvlny.cv.net> for chat@freebsd.org; Tue, 20 May 2008 10:14:00 -0400 (EDT) Received: from freebie.brann.org (localhost [127.0.0.1]) by freebie.brann.org (8.14.2/8.14.1) with ESMTP id m4KEENqx014945 for ; Tue, 20 May 2008 10:14:23 -0400 (EDT envelope-from john@freebie.brann.org) Received: (from john@localhost) by freebie.brann.org (8.14.2/8.14.2/Submit) id m4KEEN8p014944 for chat@freebsd.org; Tue, 20 May 2008 10:14:23 -0400 (EDT envelope-from john) Content-return: prohibited Date: Tue, 20 May 2008 10:14:23 -0400 From: John Brann In-reply-to: <20080519035209.GT46655@dereel.lemis.com> To: chat@freebsd.org Message-id: <20080520141423.GA33386@freebie.brann.org> MIME-version: 1.0 Content-type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary=Q68bSM7Ycu6FN28Q Content-disposition: inline X-Spam-Checker-Version: SpamAssassin 3.2.4 (2008-01-01) on freebie.brann.org References: <37f72b1f0805181418j16efd60fge243160dbfdc6789@mail.gmail.com> <20080519035209.GT46655@dereel.lemis.com> User-Agent: Mutt/1.4.2.3i X-Spam-Status: No, score=-1.4 required=5.0 tests=ALL_TRUSTED autolearn=failed version=3.2.4 Cc: Subject: Re: slide rules X-BeenThere: freebsd-chat@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Non technical items related to the community List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 20 May 2008 14:44:15 -0000 --Q68bSM7Ycu6FN28Q Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, May 19, 2008 at 01:52:09PM +1000, Greg 'groggy' Lehey wrote: > On Sunday, 18 May 2008 at 17:18:30 -0400, Jim Capozzoli wrote: > > So, I pulled out the slide rule yesterday that's older then I am..and > > I figured out how to multiply/divide on it. Is there anybody out > > there still using slide rules for day to day math? Or does anybody > > have any interesting stories/reminiscences about slide rules? I was > > considering figuring out how to do Trig on it and then taking my Trig > > final with it. :) >=20 > Heh. I don't know where my slide rule is, but it's definitely a lot > younger than I am. So the following is from memory. It applies to > the conventional slide rules that I know, with C/D scales going from 1 > to 10 at the bottom, and A/B scales going from 1 to 100 at the top > (giving squares of the corresponding scale below). >=20 > To multiply two numbers, you place the 1 on the C scale (bottom of the > slide) against the first number on the D scale (directly below on the > body). Move the cursor (or your eye :-) to the second number on the C > scale, and read off the result on the D scale. >=20 > To divide one number by another, you place the divisor the C scale > above the dividend on the D scale. Read off the quotient on the D > scale below the 1 on the C scale. >=20 > Greg > -- > See complete headers for address and phone numbers. I'm afraid I don;t use it much - but I still have mine to hand. It's on my desk, in New York City, with a cricket ball. Both objects are there to=20 confuse the locals. Both succeed. John --=20 Unreal City, Under the brown fog of a winter dawn, --Q68bSM7Ycu6FN28Q Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (FreeBSD) iEYEARECAAYFAkgy3LkACgkQV2IaDvrl+0iNTACghlpCBvjgB1q9jdNLemJ4XLBA aS4AoKlLUT5FRKnZQt7WLpBBsL3mzJuH =U2oC -----END PGP SIGNATURE----- --Q68bSM7Ycu6FN28Q--