Road
counter ''Odometre''
Mechanism
for accurate measurement of road distance (precursor of the taximetre). It
consisted of a box with co-operating screws and gearwheels attached to a moving
vehicle. One axial rod on one of the vehicle’s wheels carried the motion to the first eight-toothed (gear)wheel in
the box, while the calibrated discs on the outer top surface of the box which
were embedded on the axles indicated the distance travelled. The ratio in the
proposed Heron’s construction
is 1:8:30:30:30 so a full rotation of the last disc corresponded to 216000
revolutions of the vehicle’s wheels. By
the wheels’ diametre of
1.60 metres the distance is 1080 kilometres.
In a
variation of the device one calibrated disc had radial holes with balls that
when one of them was aligned with a corresponding hole of the box the ball fell
into a metal vessel offering easy measurement of the distance. Archimedes is
probably the inventor of this device. (Jejis Ioanis, Thousands 2, 12th century.
A.D.)
SOURCES:
"Vitruvius, On architecture, X 9", "Heron of Alexandria, On
dioptra"
The cutting
device for internal spirals (female screws)
It was an
instrument that allowed the opening up of spirals in holes. It consisted of a
powerful base with a lengthwise hole which had pegs circumferentially (instead
of a female screw) for the driving of an endless screw spiral. At the end of
the endless screw there was crosswise a triangular cutting point (regulated
with a wedge). The base was fitted onto the perforated processing object with
the endless screw of the base aligned with the hole of the object. The endless
screw, with the help of handles, was turned and driven inside the hole of the
object opening up an internal spiral with its cutter.
The Greek watermill
It was a water-powered mill for grinding grain
which continues identically in use until today. It was particularly suitable
for the hilly and mountainous regions of Greece and Asia Minor since it was
capable of functioning with small quantities of water that were moved, however,
at great speed. It constitutes the predecessor of the water turbine.
It consisted of one horizontal winged-wheel, a
vertical axle and two horizontal millstones. The axle penetrated the lower
millstone and was connected via metal connections to the (perforated at its
centre) upper millstone. The water moved the winged-wheel and the axle
transmitted the rotation to the upper millstone. The fruit from the funnel fell
into the opening of the rotating millstone, was ground between the two
millstones and came out circumferentially because of the centrifugal force. The
funnel was provided with a fruit supply regulator, depending on the speed of
the rotation.
SOURCES: "Strabon,
Geography"
The windpowered ''hydraulis'' (organ)
This is the first substantial use of wind
powering a machine worldwide. It consisted of the disposition of windpowering
and a hydraulis. The disposition of windpowering consisted of a horizontal axis
which at one end had a vertical windwheel and on the other side had a wheel
with rods. The axis was based on an iron benchframe encased in a movable
platform (which was directed towards the wind). One (articulated at the middle)
horizontal bar was flattened at one end while the other end was articulatedly
connected with the axis of the piston of the hydraulis cylinder. With the
energy of the wind the windwheel rotated and the rods hit the flattened end of
the bar and descended, successively. Therefore, the hydraulis piston lifted and
each time descended again because of its weight. Thus, the hydraulis was
supplied with the required air for its operation.
SOURCES: "Heron of Alexandria,
Pneumatica"
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