220 QUEENSLAND AGRICULTURAL gouRNAL. [1 Sepr., 1897. 
surface drains should not be too steep, or they will be likely to wear into deep 
channels, and large quantities of soil will be lost. Where permanent open 
drains wash badly, checks or blocks of timber or brush should be inserted in 
them at intervals, and buffalo-grass or common couch should be planted to 
retain the soil. Deep, open drains will be found of considerable value as cut- 
off drains to intercept seepage water coming from higher ground, which would — 
otherwise soak through the orchard and injure the trees planted in it. This 
damage by seepage water is common after very heavy and continuous rains, 
and is noticeable in many parts of the colony in soils and situations that are — 
apparently very well drained ; and since it is often several months after the rain 
before the injury resulting from the seepage shows itself in the trees, the cause 
of the injury is often overlooked. Such drains should be placed on the higher 
side of all orchards that have higher land lying to the back of them, and they 
will be found to be of great value during very wet spells. 
Sub or Underground Drains—There are many methods of underground 
drainage, and various materials are used for the construction of the drains, 
such materials including logs, brush, slabs, stones, &c. ; but the best, cheapest, 
and most efficient drains are constructed of round drain tiles of sizes to suit 
the quantity of water to be carried. 
Log Drains.—W here timber is very plentiful, drains may be constructed of 
round logs, two logs being placed in the bottom of the drain, leaving a space 
between them, and a third logis used as a cover, the earth being prevented from 
filling up the space between the logs by means of a good blinding of small 
branches, &c. Such drains need to be of considerable size, and are consequently 
expensive to dig. J do not recommend them, or, in fact, any timber drain for 
orchard purposes, as the rotting of the timber is apt to produce root-fungus in 
any fruit trees that are planted near to the drain. 
_ Brush Drains.—Place the coarser brush or branches in the bottom, and 
blind with finer brush. The drains should be not less than 3 feet deep and 
1 foot wide at bottom, and should be filled with at least 18 inches of brush. 
Brush drains, if well made, answer well in spuey, sandy, or boggy country, but 
do not last any length of time. 
Slab Drains.—The slabs can be placed in a similar manner to the stones in 
the box and coupled drains shown presently, the slabs being well biinded 
with brush. 
Stone Drains.—There are many kinds of stone drains, of which the 
simplest is a plain drain 8 feet to 3 feet 6 inches deep,7 inches wide at bottom, 
and the drain filled to a depth of 15 inches with cracked or land stones not 
exceeding 3 inches in diameter (Fig. 1). This mass of stones should be blinded 
by a thin layer of smaller stones, or by a layer of fine brush such as tea-tree. 
RDC 
Ah 
“Fig, 1.—Broken Stone Drain. Fic, 2,—Box Drain, Fria, 8.—Coupled Drain. 
——— 
a 
