'File 18/11 Buildings Repairs Agency Buildings – Correspondence re – Water pumps for the Bahrain Agency.' [‎10v] (20/150)

Have you a suitable place for a Hydram ?
The first point to ascertain is : have you a stream of flowing water anywhere on
your own land which would answer your purpose ? A well without an overflow is of no
use to work a Hydram. You must have a stream, no matter how small, of flowing water.
Where plenty of working fall can be got, a flow of even one gallon per minute will do
to work a Hydram for small supplies. The majority of Hydrams are worked by water
either issuing from small springs or else by water taken from small brooks or burns.
Wherever there is an old mill or water wheel or turbine a Hydram can always be
worked.
The next point to ascertain is : to what height and distance do you wish to raise
the water ? The horizontal distance to which the water has to be forced is of no
consequence to the practicability of the scheme (only to the expense of carrying it out),
because Hydrams can be made to force to a horizontal distance of five miles as easily as
to a distance of 500 yards, providing the vertical height to which the water has to be
raised is the same. But the vertical height to which the water has to be forced has
everything to do with the practicability, because the greater the height and the more
powerful is the Hydram required, and the less water can be raised by a given quantity
of driving water.
The next question to answer, and it is generally the most important one of all, is :
How much working fall can you get ? Now in cases where there is a dam or weir in a
stream, or a natural water-fall, this question can be easily answered, but in the case of
sluggish streams or springs rising in flat land, the answer is not so apparent.
Therefore, in the case of sluggish streams, ask yourself this question : What is the
difference of level between the surface of the water in the stream at one point, and the
surface of the stream 100, 200, 300, or 500 yards further up or further down stream ?
Even if the stream is so sluggish that the difference of level between two points 500 yards
apart is only four or five feet, it is quite sufficient to work a Hydram, if there be plenty of
driving water.
In the case of small springs on flat land, the point to ascertain is : Have you any
drain or ditch within 200 or 300 yards of the spring at a lower level than the spring,
to which you could run the waste driving water from the Hydram, and if so how much is
this drain or ditch below the spring ?
The next point to ascertain is : What is the least number of gallons per day of 24
hours the Hydram must raise ? Hydrams are made in sizes to raise any quantity of water,
from 150 gallons per day of 24 hours to 500,000 gallons per day. But a Hydram that will
raise any given quantity at full power can be adjusted in a few minutes to raise only
half that quantity, or less, if necessary.
Lastly, if the supply of driving water is not practically unlimited then an attempt
should be made to measure the quantity of water flowing, for methods of doing which
see pages 28, 29 and 30.