>> Joshua Levy: You know, people have been looking at eclipses
for thousands of years, and sometimes
those eclipses are right over their house.
Sometimes those eclipses are halfway across the world.
In the 18th and 19th and 20th centuries,
people increasingly started going on
these scientific eclipse expeditions to view them.
And the things that they brought 
with them could be pretty epic.
We have a huge range of material
at the library that documents exactly
what eclipse expeditions packed
when they went to see the totality.
Here we have a photo album that was compiled
during a eclipse expedition
to coastal Africa, Angola,
in 1889, on board
a ship called the USS Pensacola.
There were about a dozen scientists
and researchers in different fields
and hundreds of U.S. Navy sailors.
>> JJ Harbster: The accounts were ... 
there was 12 tons of astronomical equipment,
and that's not considering
the scientific instruments
that they brought
or the personal belongings
>> Joshua Levy: That’s right. 
There were other researchers doing other kinds of work.
There were people that were collecting
specimens for natural history collections,
and they needed fluid
to preserve the specimens.
There were people that were 
doing magnetic observations
and they had pendulums and things like that.
>> JJ Harbster: They also loaded up housing
because where they were going,
you know, there were no hotels.
And one thing that we noticed 
looking through all the photo albums and the
and the reports and the letters is
that there are no mentions of the eclipse.
There are no photographs of the eclipse.
There are no sketches of the eclipse.
And that is because it was cloudy
at that moment of totality.
>> Joshua Levy: Materials like this
are still enormously useful.
>> JJ Harbster: And I feel like it's also 
important and valuable for the for the public
and for kids because 
it's a way to connect to history,
and it's a way to
connect with science as well.