## [relevant to my interests]

Richard gave me this book of logarithms, Dr Bruhns’ A new manual of logarithms to seven places of decimals. It had been lurking in his family library for decades. Just look at the layout!

This is packing a ridiculous amount of information on the page. It’s dropping as many leading digits as it can: instead of showing log10 1001 as 3.0003431, it assumes you know the power of ten, leaves out leading zeroes, and shows it as â€˜3431â€™. Another trick it uses to save space is printing logs of numbers less than one (which would be negative) as 10 + that logarithm. So log10 (1/ðœ‹)Â â‰… log10 (0.3183099) â‰… -0.4971499 would be represented by 9.5028501. You get the right significand, just the result is off by 10 orders of magnitude (since 10ð‘¥+10 = 10ð‘¥Ã—1010). I guess keeping track of the powers of ten was just considered mundane housekeeping.

Richard wondered why the book hadÂ  Printed in Germany overstamped with Printed in USA:

Given the date, it’s likely that it was printed from plates, rather than a photographic offset litho process. These plates were expensive to modify, so for a student reprint of a well-established textbook, it would have been cheaper to hand-stamp over the front page.

Because accuracy of reproduction is important for log tables, the many editions of Dr Bruhns’ tables were proud to be copied from printing plates so no new errors were introduced:

Stereotyping was an old way of copying printing plates, first with papier machÃ©, and later by electroplating/electrotyping. Because it was a cheap way of getting articles and pictures reproduced in newspapers, stereotype came to have its modern meaning. The word clichÃ© also comes from the same process, as it was an onomatopoetic French word for the sound of molten casting metal hitting the papier machÃ© mould.

There are many copies of this book in the Internet archive:

Anyone want to check ’em for errors? There used to be a Prussian gold piece available if you found an error, but Prussia’s not returning our calls these days.

There’s one last surprise (or potential horror) in the book: a table of local definitions of the foot measure before metrication (and, since Dr Bruhns gotta bruhn, the logs of each number):

None of these are equal to the US customary foot, which is 0.3048 m precisely. The British and Russian foot are close, at 0.3047945 m. The US Survey foot isn’t represented either. Go on yourself, Mecklenburg and the Netherlands, with your plucky 11 inches to the foot (wat?). And I couldn’t leave you without a helpful instance of an obsolete measure symbol, the line, 1â€´ (that’s U+2034) being 1/12â€³ orÂ  2.116667 mm. Why code point space is being wasted on that and there isn’t a symbol for the wonderful HP plotter unit (1/40 mm, or 0.000025 m, which also happens to be the round[ish] 1/1016â€³) I will never know â€¦

## this is moronic

British, Irish pints prevail over EU’s imperial ban

The exceptions include pint bottles for milk and pints of draught beer and cider, miles for road signs and speed markers and the troy ounce for precious metals.

In its public consultations on the question, the EU said consumers and teachers were largely in favour of the metric system. It found industry groups, companies and national governments feared metric-only labels in part because they would disrupt trade with the United States, which does not allow such labels.

Let’s think about this: the only measure you’re likely to sell to the US isÂ  the pint. The market for items sold by the mile is somewhat smaller. The totally, utterly stupid thing about this is that UK pints are a different size than US pints (568ml vs 473ml), so they’d have to use different labels anyway. No one under 40 in the UK was taught imperial units, so who is pushing this agenda, and why aren’t they dead yet?

## a few loose tools on the workbench

Lee Valley make and sell good (if doggedly non-metric) woodworking tools. It would seem, though, that LV proprietor Leonard Lee has a rather unhealthy problem with Canada Post: postalproblem.ca.

His lengthy letters and full page ads in the Ottawa Citizen have an Incensed of Tunbridge Wells quality to them. It might be an idea to start hiding the sharp things when Leonard’s around.