TO
C. J. MONRO, Esq.
Glenlair, Springholm,
Dumfries, 20th May 1857.
I went to Old Aberdeen for Fourier, . .
but I
have forgotten what
was to be discovered out of him.
The session went off smoothly enough. I had Sun
all
the beginning of
optics, and worked off all the
experimental part up
to
Fraunhofer's lines, which were glorious to see with a water prism I
have
set up in the form of a cubical box, 5 inch side.
The only
things not generally done that I attempted last session were the
undulatory
medium made of bullets for advanced class, and
Plateau's
experiments
on a sphere of oil in a mixture of spirits and water of
exactly
its
own density.
I
succeeded very well with
heat. The experiments
on latent heat came out very accurate. That was my part, and
the
class could explain and work out the results better than I expected.
Next
year I intend to mix
experimental physics with
mechanics, devoting Tuesday and THURSDAY (what would Stokes
say?)
to the science of experimenting
accurately.
I got a
glorified top made at
Aberdeen. I think
you saw the wooden type at Cambridge. I have made it the occasion of a
short screed on rotation coming out in the Roy. Soc., Edinburgh,
presently.
Last week
I brewed
chlorophyll (as the chemists
word it), a green liquor, which turns the invisible light red.
My
pot of all the winter spinach that remained was portentous, so I
exhibited
the optical effects, which were allowed to be worth
the
potful.
My last grind was the
reduction of equations
of colour which I made last year. The result was
eminently
satisfactory.