The document discusses several astronomical and measurement instruments, including coronagraphs, magnetometers, tellurions, and helioscopes. A coronagraph allows observation of solar phenomena by simulating an eclipse, while magnetometers measure magnetic fields and are used in various applications, including military contexts. Tellurions represent celestial movements and calendars, and helioscopes are designed for observing the sun and sunspots.

1. CORONAGRAPH
A coronagraph is a telescope that can
see things very close to the Sun.
It uses a disk to block the Sun's bright
surface, revealing the faint
solar corona, stars, planets and
sungrazing comets.
In other words, a coronagraph
produces an artificial solar eclipse.

2. CORONAGRAPH
Coronagraph image of
the sunCoronagraph

3. MAGNETOMETER
A magnetometer is a measurement
instrument used for two general
purposes:
| to measure the magnetization of a
magnetic material like a ferromagnet
| to measure the strength and, in some
cases, the direction of the magnetic
field at a point in space
What is a “magnetometer?”

4. MAGNETOMETER
The first
magnetometer
was invented
by Carl Gauss in
1833 and notable
developments in
the 19th century
included the Hall

5. MAGNETOMETER
Helium Vector Magnetometer
(HVM) of the Pioneer
10 and 11 spacecraft

6. MAGNETOMETER
Magnetometers are widely used for
measuring the Earth's magnetic field
and in geophysical surveys to detect
magnetic anomalies of various types.
They are also used militarily to detect
submarines.Magnetometers can be used as metal
detectors: they can detect only
magnetic (ferrous) metals, but can
detect such metals at a much larger
depth than conventional metal
detectors; they are capable of

7. MAGNETOMETER
There are 2 basic types of
magnetometer measurement:
| Vector magnetometers
- measure the vector components of a
magnetic field
| Total field magnetometers or scalar
magnetometers
- measure the magnitude of the vector
magnetic field

8. TELLURION
A tellurion is a clock, typically of French
or Swiss origin, surmounted by a
mechanism that depicts how day, night
and the seasons are caused by the
movement of the Earth on its axis and its
orbit around the sun.
The clock normally also displays the age
of the moon, and the four-year
(perpetual) calendar.

9. TELLURION
It is related to the orrery, which illustrates
the positions and motions of the planets
and moons in the solar system in a
heliocentric model.
The word tellurion derives from the
Latin tellus, meaning Earth.

10. TELLURION
A tellurion made in 1766, used by John
Winthrop to teach astronomy at
Harvard

11. HELIOSCOPE
A helioscope is an instrument used in
observing the sun and sun spots.
The method involves projecting an
image of the sun onto a white sheet of
paper suspended in a darkened room
with the use of a telescope.

12. HELIOSCOPE

13. HELIOSCOPE
The helioscope was first used
by Benedetto Castelli and refined
by Galileo.
Benedett
o
Castelli
Galileo
Galilei