p.1

Chicago Nov, 16th 1870

Dr Sir

I have written to the observers
at Cincinnati and Duluth
as requested in regard to their
uniformly low barometers; but it would
be well for you to direct that the
first weekly reports of all the observers
be carefully examined, as they come in,
with regard to the corrections for temperature
and elevation, especially the latter.

Very respectfully
Yours

I. A. Lapham
an & C.S.O

Gen. A. J. Myer
C. S. Officer