Subject: Re: Lehman seismometer


I know I'm butting in , but can someone please tell me why people never us=
e a vacuum=20
which I would think would stop all direct air related problems,=20
but not the indirect problems like heavier air on the earths surface ?

Hi Geoff,


    Simple. If you have a panel 12" square with air on one side and a vacu=
um on the other, the total force on the panel is 2117 lbs - very nearly a=
 ton.


    Regards,

    Chris Chapman















Subject: Re: Lehman seismometer



 


I know I'm butting=
 in , but can s=
omeone please tell me why people never use a vacuum 

which I would think would stop all direct air related problems, 

but not the indirect problems like heavier air on th=
e earths surface ?



 


Hi=
 Geoff,



 




    Simple. If you have a panel 12" squa=
re with air on one side and a vacuum on the other, the total force on the=
 panel is 2117 lbs - very nearly a ton.




 


    Regards,


 


    Chris Chapman