[Taxacom] Units of length in Francis Walker's descriptions of insects

Sean Edwards sean.r.edwards at btinternet.com
Sun Nov 4 11:31:42 CST 2018


In UK bryology, I only ever knew a 'line' as 1/12" or approx. 2 mm 
(2.1167 mm). I think that lines were being replaced by the metric system 
by the early 20th century. E.g. Dixon, 1896-1924 (3 editions), Students 
Handbook of British Mosses -- he gives the 1/12" definition. He uses 
microns for microscopic measurements, then lines for up to about 1/4", 
then inches. I was brought up on Dixon -- the 1954 reprint I hasten to add!

Cook (1907, Handbook of British Hepaticae) gives spores as e.g. 
1/1170-1/880 (presumably inches, around 25 µm), but in the same volume 
for another species in microns e.g. 25 µ. He doesn't mention lines. 
Confusing times.

I can't speak for entomologists of course.

Those with access to more turn-of-(that)century literature might find 
different views, in botany and entomology.

Sean

~~~~~~~~~~~~~~~~~~~~~~~~~

Sean Edwards, Thursley, UK
email: sean.r.edwards at btinternet.com

On 04/11/2018 14:04, Mary Barkworth wrote:
>  From wikipedia:
> "The line (abbreviated L or l or ‴ or lin.) was a small English unit of length, variously reckoned as ​1⁄10, ​1⁄12, ​1⁄16, or ​1⁄40 of an inch. It was not included among the units authorized as the British Imperial system in 1824".
> I had thought it was 1/12 of an inch. Wrong, again. Does anyone know whether one usage prevailed in a particular discipline? Using 1/12 gave me numbers that seemed reasonable when looking at grass descriptions.
>
>
> -----Original Message-----
> From: Taxacom <taxacom-bounces at mailman.nhm.ku.edu> On Behalf Of Dilrukshan Wijesinghe
> Sent: Sunday, November 4, 2018 6:58 AM
> To: Taxacom List <taxacom at mailman.nhm.ku.edu>
> Subject: [Taxacom] Units of length in Francis Walker's descriptions of insects
>
> This must be common knowledge to entomologists better informed than I am: Can someone tell me if the units in Francis Walker's descriptions of insects are tenths of an inch? E.g. does "5 1/2 lin." = 0.55 inch?
>   Thanks.
>
> Priyantha
> D. P. Wijesinghe
> dpwijesinghe at yahoo.com
>
> |  | Virus-free. www.avast.com  |
>
> _______________________________________________
> Taxacom Mailing List
> Send Taxacom mailing list submissions to: Taxacom at mailman.nhm.ku.edu
>
> http://mailman.nhm.ku.edu/cgi-bin/mailman/listinfo/taxacom
> The Taxacom Archive back to 1992 may be searched at: http://taxacom.markmail.org To subscribe or unsubscribe via the Web, visit: http://mailman.nhm.ku.edu/cgi-bin/mailman/listinfo/taxacom
> You can reach the person managing the list at: taxacom-owner at mailman.nhm.ku.edu
>
> Nurturing Nuance while Assaulting Ambiguity for 31 Some Years, 1987-2018.
> _______________________________________________
> Taxacom Mailing List
> Send Taxacom mailing list submissions to: Taxacom at mailman.nhm.ku.edu
>
> http://mailman.nhm.ku.edu/cgi-bin/mailman/listinfo/taxacom
> The Taxacom Archive back to 1992 may be searched at: http://taxacom.markmail.org
> To subscribe or unsubscribe via the Web, visit: http://mailman.nhm.ku.edu/cgi-bin/mailman/listinfo/taxacom
> You can reach the person managing the list at: taxacom-owner at mailman.nhm.ku.edu
>
> Nurturing Nuance while Assaulting Ambiguity for 31 Some Years, 1987-2018.



More information about the Taxacom mailing list