This site uses cookies. By continuing to use this site you agree to our use of cookies. To find out more, see our Privacy and Cookies policy.
Skip to the content

Share this

Free weekly newswire

Sign up to receive all our latest news direct to your inbox.

Physics on film

100 Second Science Your scientific questions answered simply by specialists in less than 100 seconds.

Watch now

Bright Recruits

At all stages of your career – whether you're an undergraduate, graduate, researcher or industry professional – can help find the job for you.

Find your perfect job

Physics connect

Are you looking for a supplier? Physics Connect lists thousands of scientific companies, businesses, non-profit organizations, institutions and experts worldwide.

Start your search today


Do you recognize this antique scientific instrument?

Do you know what this is? Click on image for larger version. (Courtesy: Jean Barrette)

Do you know what this is? Click on image for larger version. (Courtesy: Jean Barrette)

By Hamish Johnston

Last week I promised readers a genuine mystery – and here it is. Do you know what this piece of apparatus was used for?

It currently resides in the McPherson Collection of physics instruments at McGill University in Montreal and its purpose has long puzzled curator Jean Barrette – who I spoke to when I was in Canada recently.

The device looks like it is designed for bench-top use and Barrette believes that it was used to study gases. Inside the cylindrical section with the half-moon window there is another small cylindrical part that can move. The small cylindrical extension to the right of the main component is an electrode input to bring high voltage inside the chamber.

“Any idea on the purpose of the instrument would be greatly appreciated,” said Barrette.

There must be a reader out there who knows what this is. Please let Jean and I know by leaving a comment below.

This entry was posted in CAP Congress 2013, General and tagged . Bookmark the permalink.
View all posts by this author  | View this author's profile


  1. Alex Ziemianski

    this book
    Spectrum Analysis: Six Lectures, Delivered in 1868, Before the Society of …
    By Henry Enfield Roscoe
    explains the state of the art of Spectrum Analysis of gases in the 19th century – I like the apparatus on page 117.

    This old science journal explains how metals were examined
    Spectra of the metalloids
    the section on Tellurium on page 178-179 describes metals heated in a vacuum tube and the spectrum being looked at.

  2. James

    My guess would be an early way of measuring the specific rotation of a gas (polarimeter) and the two holders on the stem could be for polarising filters, plus they look like they can be rotated. That said I would have thought there would have to be one filter on either side of the central chamber for that to be true.

  3. Alex Ziemianski

    Also, colleges kept a catalog of thier lab equipment in the 19th century. The equipment is likely listed in the 1899 McGill catalog – check the library for this book:

  4. This is a very accurate goldleaf electroscope. the glass bulbs would have held anhydrous cobalt chloride and the two brass clamps would have held a viewing telescope. They ere used to determine very small changes in electrostatic fields. Any more unusual instruments??


  • Comments should be relevant to the article and not be used to promote your own work, products or services.
  • Please keep your comments brief (we recommend a maximum of 250 words).
  • We reserve the right to remove excessively long, inappropriate or offensive entries.

Show/hide formatting guidelines

Tag Description Example Output
<a> Hyperlink <a href="">google</a> google
<abbr> Abbreviation <abbr title="World Health Organisation" >WHO</abbr> WHO
<acronym> Acronym <acronym title="as soon as possible">ASAP</acronym> ASAP
<b> Bold <b>Some text</b> Some text
<blockquote> Quoted from another source <blockquote cite="">IOP</blockquote>
<cite> Cite <cite>Diagram 1</cite> Diagram 1
<del> Deleted text From this line<del datetime="2012-12-17"> this text was deleted</del> From this line this text was deleted
<em> Emphasized text In this line<em> this text was emphasised</em> In this line this text was emphasised
<i> Italic <i>Some text</i> Some text
<q> Quotation WWF goal is to build a future <q cite="">
where people live in harmony with nature and animals</q>
WWF goal is to build a future
where people live in harmony with nature and animals
<strike> Strike text <strike>Some text</strike> Some text
<strong> Stronger emphasis of text <strong>Some text</strong> Some text