What is longitude and why is it important? ...(1)...
for having the Prime Meridian but the reason it was founded in 1675 was
to improve navigation, not ostensibly astronomy or horology but navigation.
And the problem that they faced was not being able to determine their
longitude when out of sight of land. Thousands of people were dying year
by year and millions of tons of ...(2)... cargo were being lost
because they couldn't navigate accurately because they didn't know their
longitude.
Now longitude is how far around the world you've come from home and
that is the same thing as time difference between where you are and back
home. The simple answer to longitude is to know what time it is back home
at the same time as you know your own ...(3)... time. Finding your
own local time is dead easy, you just look at the position of the sun
in the sky. If at that same instant you know what time it is back home
you've solved the longitude problem. But how on earth do you know time
back home? The ...(4)... way is to take a clock with you which
you set to home time before you leave but in the 1670's no one thought
a clock could be made that could suffer the rocking of the ship and the
wide variations in temperature.
So there was another method which was using the sky as a clock, the
motion of the moon like a kind of hand against the stars of the ...(5)...
of the clock. The Observatory was founded to make tables of the motions
of the moon which would give the mariners out in the middle of the ocean
Greenwich time by the positions of the stars."
1: Choose a word
formost
famous
infamous
far most
2:
Choose a word
variable
venerable
valuable
virtual
3:
Choose a word
low cal
loco
local
loaded
4:
Choose a word
obvious
oblivious
of pious
above us
5:
Choose a word
day
dye
dale
dial
What
was John Harrison's contribution? ...(6)... were dying in their hundreds and the problem was becoming
really acute. So £20,000, which is the equivalent of winning the lottery
today, was offered for any solution to the problem. And it was that ...(7)...
which produced John Harrison's chronometers which eventually solved the
problem."
6: Choose a word
soldiers
sailors
tailors
sea gulls
7:
Choose a word
a wall
ward
award
wall
Is Harrison's work with chronometers still relevant today? ...(9)... marine chronometer
and the precision watch and you can see direct evolution from his fundamental
ideas. His series of prototypes are all still here at the Museum and we
preserve them with the first three of them actually running in the galleries.
The first three are not as accurate as they were because of course they're
250 years old and more. Obviously we don't like to make adjustments and
permanent alterations to them because they're very important relics now.
We regard them rather as relics than as time-keepers. But they're still
...(10)... good considering their age."
Links for more information National
Maritime Museum - Harrison and the longitude problem
9: Choose a word
modest
modem
moderate
modern
10:
Choose a word
petty
pity
pretty
pre-tea
Check
your answers
