BUILDING AN IRRIGATION PLANT
The discovery that the Porters and Jays were really old friends opened a
floodgate of questions and answers, and the boys were telling of their
hopes and ambitions, when there sounded footsteps on the gravel walk,
and as they all turned toward the door, it was opened and in walked
Andy.
“How in the world did you know where to find us?” exclaimed Phil, after
the agent had exchanged greetings with Joy and her father.
“Or weren’t you looking for _us_?” asked Ted, with an impish grin.
“Oh, it wasn’t difficult,” smiled Andy. “When I found only one horse at
your camp, I imagined the other had got away and that you had gone after
it, and I knew you couldn’t travel very far without striking Jasper’s.
Did you find the other black?”
In answer, Joy gave a graphic account of the meeting with Petersen,
which caused the agent’s face to grow serious, for he realized the
danger to the Jays from drawing Petersen’s wrath. But with a swift
glance of understanding at Jasper, he kept his thoughts to himself, and
soon the boys launched on another recounting of their trips to and from
Bradley.
At last Phil chanced to look at the clock.
“Dear me, I had no idea it was ten o’clock,” he exclaimed. “We’ve had a
very happy time, finding a friend of father’s. And, Joy, I never ate
food that tasted so good. I hope you’ll ask us to come again.”
“The latchstring is always out to any of Winthrop Porter’s folks,”
declared Mr. Jay, heartily. “It will do Joy good to have some young
people about. I try to do what I can, but I’m old and I know she’s
lonesome, though she wouldn’t admit it.”
“The idea, Pap, me lonesome with you and all the work and the hens and
cows and horses,” and the girl put her arm affectionately about her
father’s shoulders and stroked his hair.
“Well, we’ll be over again soon and thank you again for going to Lem’s
with us. Goodnight.” And Phil advanced to shake Joy’s hand.
“Where you going?” dryly inquired Andy.
“Why, back to camp, of course.”
“Oh, I guess Jasper can find a place for us.” In amazement, the boys
looked at him and he quickly added: “It’s too dark to tramp through the
woods tonight.”
Had the boys paused to think, they would have realized that to a man
accustomed to roam the woods, this excuse was very flimsy, but they
accepted it readily.
“Will it do to leave the other black there alone?” asked Ted.
“He isn’t there,” Andy replied. Then, in response to the looks of alarm
which spread over the boys’ faces, he added: “I brought him over with
me. He’s out in your barn now, Jasper.”
“And we never heard you—that’s b—” began Mr. Jay.
“You were laughing and talking too much,” interrupted Andy. “Joy, just
tell us where we are to sleep. We must be up early, we’ve a lot to do
tomorrow.”
Quickly Joy disappeared into the other room the cabin held downstairs,
and when she reappeared she announced that all was ready for the guests,
and with hearty “good-nights” they retired.
Wearied by the events of the day, the young homesteaders quickly fell
asleep, and when he was sure of the fact, Andy arose, joining Jasper
outside the cabin, and together they guarded the buildings against any
attempt at revenge on Petersen’s part.
No mention did either of the men make of their vigil, and after a
delicious breakfast the agent and the boys returned to E 1.
“So long as I am here, we’d better build your irrigation plant,”
announced Andy when they arrived at the camp.
“But we won’t need to irrigate this year, shall we?” queried Ted.
“Depends on the season. According to the signs, I think it’s going to be
hot and dry. Anyhow, it won’t do any harm to have the plant ready, and
we can put it in in a few days and at less cost than you could hire any
one else next year or the year after. Besides, you won’t be obliged to
make a long haul with the necessary timber.”
Readily the young homesteaders assented and accompanied Andy to the west
clearing, where they chopped a few trees, then harnessed the blacks and
drove over to Steve’s camp and had them sawed into planks.
All that day and the next was consumed in hauling the lumber Steve sawed
out for them, for the boys bought several loads rather than to take the
time necessary to cut trees and draw them from their quarter.
“The first thing for you to do,” said the agent, when they returned to
E 1 with the last load of planks, “is to decide where you want your dam.
While the creek usually runs freely, you’ll need a reservoir to give a
head sufficient to cover the fields on this side. So we’ll look it
over.”
“Mr. Hopkins said the grade was just as important as the head,” Ted
remarked, as they followed the edge of the stream.
“So it is. But that applies more to the laying out of the laterals, or
branch ditches, than to the reservoir. The higher you have that, the
greater your fall of water and the more land you can cover.”
“Then why not build the dam as close to our line as we can?” asked Phil.
“Say, you boys are ‘catching on’ like good ones,” praised Andy. “That’s
just the thing to do.” And when they reached the boundary of the
section, he showed them with how little work, thanks to the lay of the
land, a reservoir a hundred feet long and as wide could be built.
This decided upon, they returned to the clearing, where the agent
constructed a simple level to establish the grade. Taking three pieces
of board, he cut one to the length of 16½ feet and another to 3 feet and
4 inches.
“The grade of the land is about 1 inch to the rod on this west side,”
said Andy, “and that is the only one you will have to irrigate.” Then he
drew out a table showing the number of miner’s inches a ditch carrying a
6-inch head of water would discharge. For the grade of 1 inch per rod,
this proved to be 37 miner’s inches, or .93 cubic feet per second, for
the ordinary-sized ditch having a 14-inch width at the bottom and a mean
depth of 5 inches.
“What’s a ‘miner’s inch’?” asked Phil.
“It’s the most common method of measuring water for irrigation purposes.
I’ve been making an apparatus to measure the water flow, and I can show
you by working it better than by explaining. But just let me finish this
grader first.”
As Andy had found the grade to be 1 inch per rod, he cut the third board
to a length of 8 feet and 5 inches, then nailed it firmly to one end of
a long board, and the 8-foot 4-inch piece to the other. This done, he
put a strip of 1-inch board under the shorter leg, then bound a
carpenter’s spirit level to the centre of the long board.
“You carry this carefully, Ted,” he ordered, giving the home-made grader
to the boy. “I’ll get my measuring board, and then we’ll go back to
where we are intending to put in the dam.”
Interestedly the young homesteaders inspected the latter piece of
apparatus after they had reached the site of the reservoir. It consisted
of a board 1 inch thick, 12 inches wide, and 8 feet long. In this had
been cut an opening 50 inches long and 6 inches wide, the centre of the
slot, on the upstream side, being 4 inches from the top of the board,
while the down-stream side was bevelled to present a sharp edge to the
water.
A second 12-inch board, with one end fashioned into a handle, was placed
against the upstream side of the slot and so hung upon the first board
that it could be shoved back and forth. On the down-stream side of the
opening, a bevelled block was fitted and screwed to the second board,
and the inches were marked.
Placing the apparatus in the creek so that it dammed it, the water
quickly flowed over the top.
“Pull that handle back until the block is at the 12-inch mark along the
slot,” directed Andy. As Phil did so, the water fell below the top of
the board.
“Now shove it back until the water is level with the top,” the agent
ordered. And when it had been done, Ted said the block was at the 6-inch
mark.
“The number of miner’s inches flowing through the slot is equal to the
total square inches in the opening, that is, near enough for all
practical purposes in a small stream like this,” explained Andy.
“Why, that makes 36 miner’s inches,” said Phil. “What was the use of
doing all this when the table showed 37 miner’s inches, with a 6-inch
head, for a grade of 1 inch per rod?”
“To show you how to measure miner’s inches and to determine a supply of
water when you do not know it, in case you should ever want to.”
“Then you won’t need to build a reservoir?” said Ted.
“Why not? This simply proves that the brook has a natural flow of about
37 miner’s inches.” Then taking out another table, he read: “One miner’s
inch equals .02 cubic feet per second; 1.2 cubic feet per minute; 72
cubic feet per hour. Now an acre-inch of water, or water to cover the
surface of an acre of ground to the depth of 1 inch, equals 3630 cubic
feet, which 1 miner’s inch will supply in approximately 50 hours. The
average amount of water for one irrigation of ordinary ground, that is
not sunbaked, is 2.3 inches. With a little calculation you can determine
how long it would take your flow of 37 miner’s inches to give you 2.3
acre-inches.”
“May we take that table, Andy?” asked Ted. “I’ll copy it tonight. We
never could remember it, and when it is time to irrigate, we shall want
to know how long it will require.”
“But what has all this to do with the reservoir?” Phil inquired, as the
agent handed the table to his brother.
“Just this. On the reverse of the table you will find the miner’s inch
represented in gallons; 27,152 gallons are required for an acre-inch.
When you get the west side cleared, you will have about 60 acres. Now 1
cubic foot of water equals 7.48 gallons. To get the required depth of
2.3 acre-inches for irrigating, you must have 8349 cubic feet of water,
or practically 62,450 gallons per acre, or 3,747,000 gallons for the 60
acres. As your reservoir will have a depth of only 10 feet, you will
have a million gallons, which will allow you to irrigate only about a
quarter of your land at one time. But, of course, it will be years
before you will have the entire 60 acres under cultivation, considering
all you have on the east side, and by that time you may be in a position
to double the size of your reservoir. In irrigating, the more laterals
you can use at one time the better, and the more water you have the more
you can use. Now we’ll lay out the course for the ditch with our
grader.”
Placing the shorter leg at the spot where the head gate to control the
supply from the reservoir was to be, he told Ted to swing the longer leg
until Phil should announce that the bubble was in the centre of the
spirit level. When this had been done, the agent marked the second spot,
then placed the shorter leg on it, and continued the operation until
they had traversed all of the section to be irrigated, the contour, as
the course is called, being nearly diagonal.
“Tomorrow we’ll plow a furrow connecting those grade marks and then
construct a ditch,” said Andy, when the grading had been finished, “or
rather begin it.”
“Where do the laterals come in?” queried Phil.
“They run from your farm, or main, ditch. For grain, they are usually 75
feet apart; for alfalfa, 90, and about 1300 feet long and they will run
here at a grade of from one-half to three-fourths of an inch to the
rod.”
“My eye! but there is a lot to this irrigation business,” exclaimed Ted.
“My head actually aches with trying to remember all you have told us.”
“It won’t seem so complicated when you are doing it,” smiled the agent.
“I hope not,” Phil said. “But I don’t see what holds the water on the
fields after you get it there.”
“Your borders. You must build banks about each field. That is the
simplest method on land that is as easy to irrigate as yours. The banks
are not high, just a furrow, so as not to interfere with passing from
one field to another to mow and reap.”
“Of course, this year, you will plant only two or three fields. In later
years you can complete the system. The chief thing is to build your farm
ditch long enough at first. Now let’s go home and eat.”
“Which makes me think, Joy insisted that we should go over there for
supper. Hurry, or we shall be late,” urged Phil.
The next morning found them at the site of the dam with horses and plow.
For two days they worked on the reservoir, and then the boys and Andy
plowed three furrows on the grade line, then ran a “crowder,”
constructed of two planks in the shape of a V, with the wide end braced
stoutly, up and down, forcing out as much dirt as possible, and for the
next three days they all worked like beavers clearing the main and
lateral ditches and shaping the borders on four fields.
To supply the water from the laterals to the fields, they constructed
boxes, open at each end, 6 inches square and 8 feet long, which were
laid beneath the banks of the laterals.
“We really ought to have plank heads at the laterals, but they are too
expensive just now, so we can use canvas dams,” said Andy. “It isn’t
worth while to spend the money on ‘tappoons,’ or metal dams, because in
a few years you will be able to put in the regular plank gate, or even
cement and steel gates, and every cent you save now is precious.”
To regulate the water in the reservoir, they put in two gates, one to be
kept open all the time to let water into the creek and the other to feed
the main ditch.
A covered flume, made of 3-inch plank, laid double, 30 feet long, 4 feet
wide, and 4 feet high, was placed at the bottom of the dam. On both
sides stout plank wings were built, the better to receive and discharge
the water, the set in the reservoir resting against the dam, that in the
ditch being carefully packed in order that no water might escape.
Fitted into the end along the farm ditch was a plank gate which could be
raised and lowered at will.
Without accident the dam was finished and the gate opened six inches,
that the creek might not be checked while the reservoir was filling.
“Now all you need to do is to plow and harrow the fields, then you can
irrigate and sow,” said Andy.