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: Artificial horizon question
    From: Bill Morris
    Date: 2009 Apr 20, 22:56 -0700

    Robert wrote (of mercury):
    "I agree with an earlier poster about mercury being ideal for
    stars. That being said, the stuff is hard to find, is highly toxic and
    therefore not recommended."
    The hazard from occasional handling of metallic mercury is probably negligible 
    and small spills probably present no hazard from mercury vapour. It is poorly 
    absorbed through the skin and it is very unlikely to find its way into the 
    gut. Small amounts are efficiently excreted through the kidneys. An 
    experimental observation of evaporation of two drops of mercury at room 
    temperature by T. Winter in 2003 showed that the vapour levels were "small by 
    comparison" with OSHA permissible exposure levels. 
    Most compounds of mercury are very poorly soluble and present little hazard, 
    but the same cannot be said of some organic compounds, notably dimethyl 
    mercury, which is extremely toxic and can be absorbed through the skin as 
    well as the gut.
    I am not advocating handling metallic mercury with gay abandon - it is too 
    expensive and hard-to-find for that - but much more toxic substances can be 
    found under the kitchen benches of most homes. And yes, I have some (a 
    litre), and I handle it without afterwards having nightmares.
    Bill Morris
    New Zealand
    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