Date: Thu, 28 Oct 1999 16:07:20 -0400

Author: (Harvey S. Picker)

Subject: Re: e/m Apparatus


Dear Gary,

These coils have 72 turns each. You'll also need the filament-to-crossbar

Crossbar no. distance to filament

1 6.48 cm
2 7.75 cm
3 9.02 cm
4 10.30 cm
5 11.54 cm

There is a reasonably complete description of this apparatus in _Cioffari's
Experiments in College Physics_ (my copy is the 7th edition by Dean S.
Edmonds, which was published by Heath). But we have the manual somewhere;
Wayne Strange, our lab coordinator, can likely help me locate it. If you
supply a mailing address, I'll be happy to send you a photocopy of the

Best wishes,

> We have a Welch 623 e/m apparatus (old - 1950's), but no manual or
>of the number of turns in the Helmholtz coils. Would any of you be able to
>help us with this information. Thanks
>Gary Karshner
>St. Mary's University
>San Antonio, Texas

Harvey Picker e-mail:
Physics Department phone: (860)297-2299
Trinity College fax: (860)987-6239
Hartford, CT 06106