# Gasoline pinwheels

**URL:** <https://boards.straightdope.com/t/gasoline-pinwheels/5141>\
**Category:** Factual Questions\
**Created:** [December 4, 1999, 3:17am UTC](https://boards.straightdope.com/t/gasoline-pinwheels/5141 "1999-12-04T03:17:00Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![drollman](https://avatars.discourse-cdn.com/v4/letter/d/f04885/32.png) [@drollman](https://boards.straightdope.com/u/drollman)\
**Post date:** [December 4, 1999, 3:17am UTC](https://boards.straightdope.com/t/gasoline-pinwheels/5141/1 "1999-12-04T03:17:00Z")

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As I child, I remember a glass globe on the side of the gas station pumps. Inside was filled with a liquid (I presume to be gasoline) and something like a colourful pinwheel or a couple of marbles that would spin or jump around while the gas was being pumped. Why do we not see them anymore? Did they ever serve a purpose to begin with?

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With God as my witness, I thought turkey’s could fly.

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**Author:** ![JBENZ](https://avatars.discourse-cdn.com/v4/letter/j/b77776/32.png) [@JBENZ](https://boards.straightdope.com/u/JBENZ)\
**Post date:** [December 4, 1999, 4:00am UTC](https://boards.straightdope.com/t/gasoline-pinwheels/5141/2 "1999-12-04T04:00:00Z")

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I remember seeing those on old manually operated pumps (where you pumped gas up into a reservoir by hand which then flowed down through the hose by gravity.) I think the butterfly was to tell you that gas was flowing since there was no pump motor to listen to or guage to read.

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JB  
Lex Non Favet Delicatorum Votis

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**Author:** ![NanoByte](https://avatars.discourse-cdn.com/v4/letter/n/ecc23a/32.png) [@NanoByte](https://boards.straightdope.com/u/NanoByte)\
**Post date:** [December 4, 1999, 4:03am UTC](https://boards.straightdope.com/t/gasoline-pinwheels/5141/3 "1999-12-04T04:03:00Z")

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Well, I would suspect that, because quantity gauge didn’t show less than tenths of gallons, and the flow was slow, that the “pinwheel” made the pumper readily aware when gasoline was flowing.

The pumps before that merely had cylindrical glass containers at their tops, with graduated vertical gallon scales on them – I think, down to a quarter of a gallon, but you could also see some fluid motion and maybe bubbles when the gas was being pumped.

People back then could also have buried gas tanks at their urban residences, with pumps and open vents. I remember us kids playing with these, in the '30s, in ways I don’t want to think about.

Ray (remembers the _ **real** _ self-service)

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**Author:** ![Fear\_Itself](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fear_itself/32/19637_2.png) [@Fear\_Itself](https://boards.straightdope.com/u/Fear_Itself)\
**Post date:** [December 4, 1999, 4:21am UTC](https://boards.straightdope.com/t/gasoline-pinwheels/5141/4 "1999-12-04T04:21:00Z")

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From the Tiger Hightest Magazine [Gas Station Collectibles Glossary](http://www.galstar.com/%7Ehightest/glossary.html#S)

> [@](#):
>
> **Sight Glass** - A clear glass device used on gas pumps, beginning in the 1940’s, through which gasoline flowed, allowing customers to view the product being pumped into their vehicles, so as to give visual verification of the quality and quantity of the purchased product.

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TT

“Believe those who seek the truth.  
Doubt those who find it.” --Andre Gide

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**Author:** ![drollman](https://avatars.discourse-cdn.com/v4/letter/d/f04885/32.png) [@drollman](https://boards.straightdope.com/u/drollman)\
**Post date:** [December 6, 1999, 8:41pm UTC](https://boards.straightdope.com/t/gasoline-pinwheels/5141/5 "1999-12-06T20:41:00Z")

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Thanks to all, Especially TT!