[GreenKeys] Ebay Listing

[Bruce Gentry]

I spent 32 years in the elevator business. Hundreds of times I answered 
service calls in schools, and probably 80 % of the people wanting to see 
the car top and hoistway and asking truly interesting questions were 
girls. Once boys were about 13 or 14 years old, they would rarely admit 
to or express any curiousity or  ask a truly intelligent question. Even 
when some of them turned 18 or 19 and became apprentices under me, they 
wanted to learn the minimum to get by and get a paycheck.  It's more 
than a little scary, and one of the reasons I asked some months ago 
about women  servicing and repairing teleprinters.

       Bruce Gentry, KA2IVY


On 6/26/15 1:18 AM, tony.podrasky wrote:
> GN OMs;
>
> In Junior High School science, the teacher demonstrated how
> sound travels through air - and how it doesn't through a vacuum.
>
> He took an electric doorbell and put it on a rubber platform
> and placed a bell jar over it. You could hear it ringing. Then
> he turned on a vacuum pump and drew out all the air in the
> bell jar. As the pressure went negative, the bell was less and
> less audible. Pretty soon you could barely perceive it.
>
> Then the teacher stopped the pump and opened a vent on the side
> of the bell jar and as you heard the hissing, you could hear the
> bell get louder.
>
> When the experiment was done, he asked the class:"what happened
> when I started the vacuum pump?".
>
> The smart little girl said: "as the vacuum pump removed the air
> in the bell jar, there was less MEDIUM to convey the sound of the
> ringing bell to the outside world - until there was no air left and
> we couldn't hear the bell anymore.
>
> The class was dumbfounded - and the teacher in awe. The teacher
> congratulated the girl for her answer.
>
> Then the teacher asked: "what happened when I opened the vent?"
>
> The class dumb-guy yelled out with glee: "The Vacuum EX-CAPED!".
>
> The expression on the teacher's face was PRICELESS!
>
> UE,
> K2EAA - TONY
> NNNN
> ZCZC
>
>
> On 06/25/2015 08:55 PM, hwhall at compuserve.com wrote:
>> Ieagerly await when we can 3D print vacuum tubes. And I'm really
>> interested in how the vacuum gets applied.  ;-)
>>
>> Wayne
>> WB4OGM
>