Odd floppy drives (Helitron)

[Chuck Guzis]

On 9/24/2005 at 11:45 AM Fred Cisin wrote:
><nitpick>
>grooves "like a phonograph record" would be "SPIRAL", NOT "helical".
>"Helical" would be like a spiral stair case, or threads on a bolt.
>Some of the early (Edison?) sound recorders DID cut helical threads on the
>outside of a cylinder.
></nitpick>

I think a little leeway can be granted here--after all, the common garden snail, helix hortensis (whence comes our word "helix") is actually more of a spiral than a helix:

http://www.weichtiere.at/Schnecken/galerie/galerie_1024.html

And the species of tuba known as a helicon has a distinctly spiral shape:

http://www.horncollector.com/Low%20Brass/Helicon/Helicon%201.jpg

Perhaps an easy way to remember the difference is that a helix is the shape of a spiral staircase! :)

Cheers,
Chuck