GARDEN lERIGATION ITS ADVANTAGES AND LIMITS. 37 



be watered. Thus, for example, we will suppose that it is required 

 to water five acres of land, and that we have near by a never- 

 failing pond or river ; we can locate a steam pump near the river, 

 and while at work watering we load the safety valve upon the 

 delivering water pipe at fifteen pounds per square inch, which cor- 

 responds to a head of about thirty feet of water. We have three 

 hundred feet of iron pipe, two inches in diameter, and one hundred 

 feet of India rubber hose, one and a half inches in diameter, for 

 delivery of the water ; this apparatus would be capable of deliver- 

 ing forty-five gallons per minute, or twentj'-seven thousand gallons 

 per day of ten hours ; enough for the thorough wetting of one 

 acre per day, or every acre of the five once in five daj^s ; by run- 

 ning nights, ten acres could be watered with this apparatus. 



Where it is only desirable to water a limited area of land — less 

 than an acre — the windmill furnishes a cheaper source of power than 

 the steam pump. To make it available, however, large storage of 

 water must be provided at a high level, so as to admit of keeping 

 the mill at work during stormy weather and storing the water until 

 needed. A windmill for pumping, costing, with pump and tank, 

 about $500, will furnish water enough for the irrigation of one or 

 two acres of land, provided storage can be supplied at a high level 

 for 200,000 gallons of water. To provide this storage might cost 

 as much as to provide steam pumps ; and any decision with regard 

 to details of this kind, would depend upon the varying circum- 

 stances of each particular case. It is onl}' proper here to call 

 attention to the fact that where elevated reservoirs can be easilj' 

 made, and the amount of water needed is not over 10,000 gallons 

 daily, the windmill is, without doubt, cheaper power than steam ; 

 when the amount of work to be done is much larger, steam is in 

 general to be preferred. 



4th. Tlie Advantages and Lbnits of Garden Irrigation. This 

 question resolves itself into the practical one of whether it will 

 pay to irrigate gardens ; of course gentlemen who have almost 

 unlimited funds to spend upon their pleasure grounds, understand 

 the advantages of irrigation as a garden luxury, and will have water 

 at any cost ; it is here proposed only to consider briefly how far a 

 practical gardener, who makes gardening his source of living, can 

 afford to irrigate. This will depend first on the cost of water. 



Water is supplied by the public works in some of our cities at 

 25 cents per thousand gallons. This is a rather high rate ; at this 



