Welcome to the NavList Message Boards.


A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

Compose Your Message

Add Images & Files
    Re: napier and logarithms
    From: James N Wilson
    Date: 2009 May 31, 20:33 -0700

    You asked:
    "I wondered how these marks had been put into my copy, and indeed,
    they had been laboriously drawn in, in manuscript, after printing. By a
    stroke of luck, the museum happened to have a second copy of that same
    edition. [It's hard enough to lay hands on a 17th century book, never
    finding two identical copies in the same place] And indeed, those L
    in the two copies, were identical; they had indeed been printed.
    "So now, at long last, I get to my question. HOW were they printed? The
    museum librarian hazarded a guess that the printer had somehow inserted
    of bent wire into his block, to pick up the ink and transfer it. But how
    would they be held in place? Does anyone know enough about printing to
    a guess?"
    As a journeyman printer in my youth, I'll venture my understanding.
    Printed lines were achieved by using "rules," a thin (two point) type
    height strip which could be inserted between columns, for instance. But
    they weren't bendable, breaking easily because they were type metal,
    mainly lead. Now, I'm surprised at the vertical lines in your copy--if
    they were rules, they would be straight, and they're not. That could be a
    consequence of scanning. Significant distortion is evident throughout the
    page, and type isn't at all moldable. But I can't explain the L shapes as
    distortion due to scanning.
    The size of the type is larger for the left digits, and smaller for the
    right. That would leave enough space for a rule to be inserted under the
    right hand type. But it couldn't be bent. And the rules take up space,
    and the spacing between numbers isn't greater where a vertical line is
    present. And they're all different, which I associate with hand-drawn
    lines. The idea of wires doesn't track, because printing is done with
    heavy pressure, so type has to be sturdy. The days of pages of individual
    type were a lot more difficult. Everything had to fit together and needed
    space. We didn't know better, so we just made it work.
    Lithography can be ruled out, since it wasn't invented until 1796, and
    besides, it was more suited to art than text and numbers then.
    Sorry, but my expertise ends here. And I was born three centuries too
    late to really understand.
    Jim Wilson
    Free information - Learn about Email Marketing. Click now!
    Navigation List archive: www.fer3.com/arc
    To post, email NavList@fer3.com
    To unsubscribe, email NavList-unsubscribe@fer3.com

    Browse Files

    Drop Files


    What is NavList?

    Join NavList

    (please, no nicknames or handles)
    Do you want to receive all group messages by email?
    Yes No

    You can also join by posting. Your first on-topic post automatically makes you a member.

    Posting Code

    Enter the email address associated with your NavList messages. Your posting code will be emailed to you immediately.

    Email Settings

    Posting Code:

    Custom Index

    Start date: (yyyymm dd)
    End date: (yyyymm dd)

    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site