INDUS SOCIETY WATER SERVICE
-------------------------
John Pazmino
NYSkies Astronomy Inc
nyskies@nyskies.org
www.nyskies.org
2019 February 28
Introduction
----------I sat a lecture at the American Institute of Archaeology on
2019 February *** about the Indus civilization. 0This was at Hunter
College, sponsored by AIA's New York Section .The talk was by Dr
Rite Wright, of New York University.
This lecture, when I got the notice, struck my curiosity. I'm
interested in ancient cultures generally, specially for their
astronomy, but I just never heard of a society in the Indus River
area. There certainly could be one, being that rivers are favorite
homes for human societies. I was plain not aware of any. I went to
fill this hole in my knowledge.
The lecture was at Hunter College on Manhattan, one of several
venues hosting AUA lectures. I arrived at Hunter College from work at
18:10 EST thru uderground corridor connecting it to thee Lexington Av
subway line.The talk began at 18:30 in a side room set up for small
audience presentations.
Indus culture
-----------
Dr Wright gave a thoro overview of the Indus society, and most of
the audience, like me, didn't know about it until her
presentation. While the entire presentation was thoro, I here deal
with one major amazing feature: water supply and waste disposal. This
was a surprise for me! It wasn't mentioned in the lecture notice.
It specially related closely to my career as an engineer in water
resource management. In this section I give a brief overview of the
Indus as background and a jumpoff for your own reading.
Indus was first discovered in the 1920s as remains of a large town
Harappa, in Punjab province of Pakistan. The society is sometimes
called the Harappan society. other towns were found over the years,
and e even today new towns and other remains are continually
uncovered. the Indus culture is a really new one in archaeology, while
the Babylonian and Egyptian cultures are already under study for over
150 years.
The Indus land was in the Indus river vwatershed in modern
Pakistan and India. The society was founded as a series of towns along
the rivers, with farms around them. Few Indus people lived in rural
areas. The Indus culture flourished in the few centuries around 2000
BC, with earlier relics dated to at least 3000 BC. As best we know
now, it is the earliest urban-based society.
The towns were built on rectilinear streets aligned N-S, E-W.
There were no strong circumvallations, all being too weak against
enemy attack. They seem to be barriers or fenders against flooding by
the adjacent rivers. So far we don't know of major wars with the Indus
people and the Indus is sometimes characterized as having a peaceful
calm existence.
The people lived in brick and clay houses set square within the
street grid. They are almost all single-story structures with some
fancier ones of two floors. Public or official buildings were
generally on higher ground and upland from the rest of the town.
One early realization by archaeologists was the absence of
temples, shrines, monuments, like those in most other ancient
cultures. It seems Indus had no pantheon of gods who modulated its
fate. Nor did it have a episcopic ruling class, like kings or chiefs.
The government of Indys was distributed and crewed by merchants and
traders, not nobility or royalty.
In the last ten or so years unearthed remains from Indus
cemeteries show that the society allowed newcomers from other parts of
India and Mid East. They lived out their lifes in the Indus towns like
native Indus folk.
Many skeletons found in groups, as if buried together, showed
injuries like from warfighting. Yet we don't have god information of
wars in the prime years of the Inudus people. The graves did not have
weapons, commonly buried with their owners in other cultures.
The society lived by agriculture of both corps and livestock. It
apparently produced enough to sustain itself and a thriving trade
with other peoples.
Indus had domestic animals for traction, motor power, protection.
It captured birds and fish for food. many kinds of animals, with
several wild ones, were objects of worship.
The major manufactured product in Indus was jewelry. This was made
from beads of gemstones or gold as trimming and necklaces. Indus made
seals, inscrbed skips of baked clay. These seem to be tags, labels,
altho they could be ornaments. They depict animals, birds, fish, but
none show superhuman anthropomorphic creatures, like the gods of other
ancient societies.
We have no evidence Indus knew the metal iron. Indus spanned the
Bronze Age and faded out in the early Iron Age. It did trrade gold,
silver, gemstones, copper.
The Indus writing was pictographic but as yet is not well
deciphered. The main impediment to deciphering the writing is the
scarce examples. The seals have only a few glyphs with no hint of
translating to text or even words. The building have almost no writing
on them and we so far have no inscribed tablets, stelae, papyri, other
scriptive medium. We rely on physical artifacts and remains to suss
out the history and culture of Indus.
Indus astronomy
-------------
I naturally was keen to hear about Indus astronomy, or generally
its science, at this lecture. It in the stead stayed on the physical
structures. When I got home I began looking for material on the
astronomy expertise of the Indus people.
I supposed that such an advanced society must have developed a sky
competence for timekeeping, calendar, surveying, tracking seasons and
weather, perhaps ocean navigation. If Indus did not build its own
astronomy it surely borrowed or adopted the astronomy of cultures in
Mesopootamnia and India.
I'm keeping this here article focused on the water resource
operations and leave the astronomy for a future endeavor.
Looking over several references it does seem that understanding of
Indus astronomy is still incomplete. We know the Indus for barely a
hundred years, still can't confidently decipher its writing and
language, haven't found positive relics associated with astronomy.
None of the usual astronomy histories mention the Indus. They
discuss Egypt, Babylonia, Persia, India, China, ut fly over the Indus
watershed. On the other hand it looks like in the 2000x-2010s interest
in Indus science/astronomy picked up.
I note here just one tidbit. The Indus used a lunar calendar. It
has 12 months of alternating 29-30 days. Its 254 day length is about
0.4 day shorter than a true lunar year. After 30 months a leapday is
added to the 30th month to get back in synch. The month began at or
near a Full Moon, with the slippage of that 0.4 day each year.
.
Water system
----------
I was particularly fascinated by the Indus systems for furnishing
water to the towns and handling waste water. This hit me as a
stunning example of early efforts to manage water resources, a subject
integral with my career. I leave the rest of Dr Wright's lecture to
concentrate on the Indus water systems.
Indus is so far the earliest society to have a coordinated scheme
of water supply and disposal. Other cultures, even those millennia in
the future, let their people fetch fresh water as they can and toss
out spent waste where ever they can.
Indus towns did not take fresh water from the rivers. In the
stead, each house or cluster of houses had a well. Larger buildings
had deeper wells worked by Persian wheels, explained later. Wells were
brick shafts, probably the first such construction known. Neither
Egypt nor Babylonia had brick-walled wells.. Their wells were raw pits
or shafts with no lining.
The Indus watershed is in a generally dry region, collecting
water from the Himalayan mountains in northern Pakistan. The watershed
also filled from monsoons, causing the annual flooding season.
Each town had hundreds of wells, perhaps a full thousand in the
larger ones.We don't know for sure how the water table was surveyed
for proper location, spacing, depth of the wells.
The house wells were maintained by the residents. Public wells,
mostly for public baths, tanks, irrigation, were run by the town.
It apparently wasn't practical to collect rain. The territory if
the nbdys culture was dry with a dense monsoon season, The massive
rain refilled the wells sufficiently to do without capturing water
directly from the sky. Some water did fill reservoirs and open tanks,
which was welcomed extra supply.
Dipping pole
-----------
Indus used two main methods to lift water from the wells. There
was also the trivial one of lowering down a rope-&-bucket, letting it
fill, and hauling the bucket up to the surface. This worked for
shallow water table, a couple meters, and occasional need for water, a
couple times per day.
Wells for a large house, cluster of houses, commercial/office
building used a dipping pole. The name varies widely across cultures.
This is a stand next to the well with a horizontal axle on top. A
long, some ten meters, pole pivots on the axle like a seesaw or lever.
It is off-centered on the axle. The longer half carried a rope-&-
bucket over the well. The short half carried a sack of stones, sand,
&c as a counterweight. This is heavy enough to lift the long end when
its filled bucket of water.
In use the operator pulls or hangs onto the rope, letting the pole
swing down under his weight. The bucket enters the well and fills with
water.
When the bucket is full, he lets the pole swig up, pulled by the
counterweight, to raise the bucket to the surface. He empties the
bucket into other vessels for use.
This dipping process is repeated to satisfy the instant need from
the well.
The construction is simple enough for a group of handy persons to
build, but it is too frail to endure decay over the millennia. We
probably have no examples of dipping poles directly from ancient
times.
Persian wheel
-----------
The other method for lifting water from a well is the Persian
wheel. It also has several alternate names. The Persian wheel is a
large machine, several meters tall and ten or more meters around at
/the base.
It consists of a stand over the well with a horizontal axle. This
supports a vertical wheel, like a Ferris wheel. This, the lifting
wheel, is connected by cogs to a flat disc on the ground, the drive
wheel, on a vertical axle. An ox, other motor animal, walks on the rim
of the drive wheel, turning it and the lifting wheel.
A rope belt or chain is looped over the lifting wheel. The belt's
links engaged cogs on the wheel. The flower end of the belt extends
down into the well. as deep as 20 meters. Deeper than that the chain
becomes too heavy and dragged for animal power to move it.
Buckets are tied to the belt, all facing in one direction. One one
side of the loop they face up; other, down.
As the lifting wheel turns the down-facing buckets are carried
into the well, fill with water, round the lower end of the chain.
They, now facing up to hold their water, ride back to the surface.
As the filled buckets round the top of the lifting wheel they tip
downward to spill their water into collecting chutes and channels.
These route the water to tanks, ductwork, irrigation.
The Persian wheel was used for large water needs or continuous
flow, and were built and run by the town. It required a team of
skilled crafters and a trained crew to operate and maintain it.
Wright didn't describe these devices specificly but mentioned them
in passing by heir native names. The dipping pole and Persian wheel
were known in Indus times and remains of the wheel are found in many
Middle East and India ancient sites.
Believe it or not, both mechanisms, newlyy built ones, are still
used today thruout the Middle East in rural areas. They are common
attractions for tourists.
Plumbing
------
The Indus people were the first to build real plumbing, with pipes
and outlets, in their buildings. The water taken from a building's
well was poured into a tank on the roof or top floor. It then ran down
to the rooms thru clay or terra cottta pipes along the walls to the
outlets. These were the faucets, capped with wood plugs, for the usual
household functions.
Toilets were not worked by the fresh water pipes. The toilet was a
wood or stone plank with fanny holes, set on a stand over a drain
pipe. it was flushed by dumping a jug of 'gray water', water saved
from washing or cooking, into the toilet. This whooshed the deposits
into the waste drains.
In small houses, one or two rooms, the network of pipes was
simple. Even so, the pipes clogged or leaked. The practice was to make
the pipes in short lengths that sleeved together. The joint was
'trailing' with water passing from the narrower end of a pipe into the
wider end of the next. A defective segment could be removed and
cleared or replaced.
Pipes, most other items of local need, were made in factories, in
each town.
Waste water from upper floors was ducted by pipes to the drain
ditch outside the building. From there the water flowed into the
town's sewers along the streets.
Water disposal
------------
After the fresh water was used yo it had to be disposed. The Indus
civilization is the first to develop a mature scheme of waste water
handling. The system was so far ahead of its time that it wasn't
equaled n scale and scope until the 19th century of our era.
from Wright's pictures and others I later examined, Indus towns
built drains and sewers way to complex to describe fully here. In
The streets in an Indus town were built from the start flanked by
drainage trenches. These varied from shallow channels to over a meter
deep. These collected drainage from the buildings and ducted it to
either the river or cesspools. The channels were sloped for gravity
flow with no known siphons or hydraulic jumps.
Any property in the town had access to a nearby channel to release
its waste water into. It digged its own feeder ditch to a conveniet
channel. It was either left raw or lined with clay.
The trenches were neatly finished in smooth surface brick and
gypsum mortar, Those remaining today seem reasonably water-tight.
The smoothed walls and bottom let the water flow with minimal
obstruction or interference.
Due to the high risk of clogging, the tow sewers were open air for
workers to get inside and clear the blockage. They also had to enter
the trenches to scoop out s
solid matter to spread on farms as fertilizer. To protect the
trenches, brick or stone slabs were laid over them. This allowed
traffic to pass over and inhibited casual tampering.
The trenches were a network, with small branches merging into
larger ones. The largest channels, the trunk mains, eventually leaded
to the river or town cesspools. As the cesspools dried out the solid
matter was used to fertilize the farms.
We don't really how the sewers were maintained and repaired. It
must have taken a large exercised team of workers to look after it,
under some roof agency of the town. Some archaeologists believe the
crew was made of slave;, others, enemy prisoners. While the civil
works were substantial, the cleaning, replacing broken parts,
protecting against molests or attack required 24/7 attention.
Modern features
-------------
The sewers had screens or strainers and, yes, water traps. The
screens were plates of wood with small holes. These were set into the
trench to filter solids from the water floe. These was mostly trash
and rubbish that was scooped out and brought to the river by town
wagons. The screen was pulled out from time to time to let a stronger
water flow current the trench.
The traps were pits or sinks, also of brick integral with the
trench. They were built at intervals along the sewer where heavier
solids fell into while the light material and water passed along the
trench.
Where a sewer crossed a major street a deck of stone or brick
wasn't strong enough to protect the trench. The cross street had a
culvert, a tunnel to let the sewer pass under it.
To work on a section of drain channel it was cut off from the
network by wood boards, sealed with clay, at ends of the work area.
Water was diverted from the work area by boards placed to deflect flow
to other segments of the drain network.
Conclusion
--------
The Q&A following the lecture was prolonged, about a half hour,
because few of the audience knew the Indus culture, I asked about any
Indus understanding of groundwater and regulation of water withdrawing
from it. Dr Wright explained that the study of Indus is still new with
many of its features as yet uncertain.
After the meeting let out we walked to a reception area. A lunch
table there was filled with hefty snacks.We munched on salads,
sandwiches, sweets.I then went to the subway, entering it thru direct
passage from Hunter College.
This lecture was, uh, wonderful! It added a whole new region of
ancient history for me to investigate. This is specially for Indus
astronomy, which was not part of Dr Wrugght's talk.
It added new insight to the history of my own career in water
resource management and insight into early efforts to handle
environmental concerns. Recall that as late as the mid 20tj century
many US towns had only crude sewers and weak fresh water systems.
Collaterally the Indus society shows hoe utterly essential liquid
water is to sustain a prosperous people. It was fortunate to have
continual strong rain to replenish the ground water and a handy river
to receive its wastes. Even for a small town of a few thousand
residents, the volume of water passing thru it is huge.
This must be a capital concern when speculating about human
habitation of other planets. None within even conceivable reach of
Earth has open surface water, a water-driven weather regime, or
geological recycling of water. Water may exist in shadowed craters on
the Moon, but once its taken out to serve a lunar colony, while it be
replaced by natural means? Where is the waste water released to? Mist
the colony hope water tanks will reliably come from Earth like they do
for ISS