JS

PROF. T. CASPERSSON
SCHEELEGATAN 17 May lst 1961

STOCKHOLM Kk
TEL. 501061

Dear Joshua:

At last I am back in Stockholm to stay
there. I have been doing some thinking about
an UMSP for very small objects, stimulated
by our talks, your telephone call and to some
extent annoyance over the new Russian "first",

Enclosed I send a very crude plan for
a possible way to try. If one really wants to
get at particles of bacteria-size I feel one
should carry a line incorporating refocusing
at each wavelength and that is the central
thing in the plan. It would be much nicer if
one could work with truly achromatic lenses add
thus work without refocusing - however I believe
all existing lenses are not perfect enough for
that and the chance for a new lens within a fww
years is very slight indeed because of the enormous
work needed for such a development, involving
new lens materials and cemenrs.

With this I mean that one should try
to explore the existing lenses as far as possible -
that is a rhing we can do and have started
doing. In addition to that however I feel if
it advisable to work on a refocusing system at
the same time - because of the time limit.

e enclosed plan is very crude and sa

also the langauge ig not good. However, not k
knowing ymuxx the extent of your interest I feel
it might be permissible to send it in its present
shape. Furthermore I expect Dr Loevinthat will
come here next week.

It would be nice to have a clear under-
standing about what you would like us to do.
At present I gather that we should take absorption
spectra of different types of objects as discussed
in Stanford and we are now to wait for some
objects from you. In addition to that we
shouladsftnd out how well achromatized the exxsting
lenses are. We have just started to work witfh
the 1.25 Zeissilens- but have no great expecta- ,
tions about &kx its achromatism below 26CC A, vi?
This work is not very inspiring and invol€s_
fairly much technical work. It can be carried
for a year with the organization we spoke of,
of an half-time young academic assistant herefor
which we have, as you know got about 25CC dollars
from the Swed Nat. Sc.Research Council -
plus measuring work by a highly qualified tech-
nician. To some extent the latter can be made
in our routine line. If the work has to be more
productive 1/2 to 1 person should be put on that,
what would mean 2500 - 5.500 dollars extra for
a year, as I told you when you asked in Stanford.
Of the plan enclosed we would only be
willing to do the spade work - finding out .
wage is feasible and the basic arrangemnts degen
oM"Oscillating focusing" etc. That would
include some work in workshop and some purchases
amounting to perhaps an additional 2 O00 dollars,
The physicists here would be glad to collaborate
(in my institute) without any extra arrangements
outside what could get into the budget mentioned
above.
You have to tell if you are interested
and in which way. Else we do not do anvthineg.
ft would be easy for me to find the money here,
but I understand that you are not very enthusiastic
about the then unaveidable opportunity for the
press to see all papers and make private comments
and specualations without asking me ~ the way
they have already done once. If you should be
interested in furnishing some funds at some time

I epurigetso point out that if they are given
as to the institute mexmaxinxtieee for-—
a_piece—of-work I have to ask permission at the
Department of Education to. receive it and then
again the whole thing passes through a press
office where anyone can read anything.

If the grant were yours and we made agreement
that £mx a lump sum , for which I am responsible,
would cover the costs for #@.work here in Sweden,
which we had agreed upon - then I cannot see

that it would be necessary for me to @j——~>
PROF. T. CASPERSSON
SCHEELEGATAN 17
STOCKHOLM K
TEL, 5010 61

ask for special permission and then it would
only be a thing between the two of US.

All this just to clarify the points about
our official procedures and the relations to
the press - we have, I am sorry to say - very
few responsible science reporters in Sweden.

With best personal regards
I am yours

Joby