No. 6. 



Span Level for Draining. 



179 



For the Farmers' Cabinet. 

 Review of Agricultural Works. 



Mr. Editor, — I am a subscriber and a 

 faithful reader of the Cabinet; indeed, I might 

 almost say it is never out of my hands, for I 

 keep the five volumes, as well as the new 

 numbers, always by me, not only referring to 

 them when I want information on any par- 

 ticular subject relating to agriculture, but 

 inany a leisure moment do I fill up by their 

 perusal. The form of the publication is pecu- 

 liarly adapted to this, and the articles gene- 

 rally being short, a few moments, otherwise 

 idle, can be most profitably employed. One 

 may, for instance, while waiting for dinner, 

 obtain information worth more than years of 

 subscription to your paper, and many good 

 dinners besides. 



My object now, however, is not to com- 

 mend the Cabinet, which would lead me into 

 a very lengthy epistle, for " too much cannot 

 be said in its praise," but to draw your atten- 

 tion to the propriety of devoting a few of its 

 columns, from time to time, to the review of 

 works on agriculture, particularly the new 

 publications of the day. This would be in- 

 teresting to your readers generally, and of 

 great use to such as reside in the country ; 

 tor when they see in the newspapers a work 

 advertised, they have no means of ascertain- 

 ing its practical value, until, perhaps, an op- 

 portunity is aflx)rded of a visit to the city, 

 when the work may be only superficially 

 glanced over at the bookstore before purchas- 

 ing. Now, a good review and criticism would 

 obviate this, besides the utility of the articles in 

 drawing attention to the correct or fallacious 

 reasonings of the author. Indeed, even a list 

 of the new publications would be interesting. 

 Much advantage would be derived, also, from 

 a notice occasionally of standard works (agri- 

 cultural, of course) ; and a corner of your 

 paper thus devoted, would add to its interest. 

 A correct taste would be aided ; for those dis- 

 posed to study, would be directed to profitable 

 works, and many induced to read more on the 

 subject, and to better advantage, if their in- 

 terest was excited by a judicious critical no- 

 tice of a good work. 



There are yet a few of the " old school" 

 farmers who have a prejudice against reading, 

 or "book-farming," as it is called; but I be- 

 lieve that the time has passed, when it is 

 doubted that intelligence and research pro- 

 duce beneficial and profitable results upon 

 any subject to which they are applied ; nor is 

 agriculture so poor, as to furnish an exception 

 to the rule. 



Hoping you will excuse the liberty I have 

 taken in attempting to improve that which 

 already is so excellent, I am, &c., 



V. 



Cazenovia, Dec. 16, 1841. 



For the Farmers' Cabinpt. 

 Span Level for Draining. 



The short article under this title, trans- 

 ferred from the Southern Planter to page 161 

 of the last number of the Cabinet, contains 

 about as strange a jumble of ideas as could 

 well be squeezed into so small a space. The 

 writer first sets out with stating the import- 

 ant advantages of draining, &c., which is all 

 well enough. Next comes the important in- 

 formation, that open drains require a fall of 3 

 inches in 15, to enable the water to drain off 

 effectually, which is afterwards stated to be 

 3 inches in 15 feet ; who made the mistake, 

 the writer or the printer, I know not — but 

 let it pass. Then comes a description of his 

 span level, which turns out to be identical in 

 principle, and very nearly so in form, with 

 the rafter level — an instrument long known 

 and used for similar purposes. 



I would observe in this place, that if any 

 farmer or land-holder has a large body of 

 land, or even a large field to drain, he will 

 save himself an infinite deal of trouble, vexa- 

 tion, and disappointment, by discarding, in the 

 first instance, the use of the span level, and 

 employing a competent person, with proper 

 instruments, to ascertain the whole fall to be 

 obtained, and so lay out the drains that it 

 shall be properly distributed among them. 

 Then, if the depth it will be necessary to 

 sink the heads of the drains to catch the 

 water to be carried off, is once ascertained, 

 and the size of the drains fixed on, an esti- 

 mate of the whole amount of excavation, and 

 of course of the cost of the work, can be 

 readily made, previous to commencing other 

 operations. The span, or rafter level, when 

 properly made, will then be found a useful 

 heip in finishing the bottom of the drains. 



The strange assertion, that "in open drains 

 it has been found by experience that to carry 

 off water effectually, a fall of 3 inches in 15 

 feet is necessary," merits further notice. A 

 fall of 3 inches in 15 feet, is 88 feet to the 

 mile, or a fraction less than an angle of one 

 degree ; and about the grade considered de- 

 sirable for a M'Adamized road. Of land that 

 requires draining, we do not believe there is 

 one acre in 100 that has a fall of 68 feet to 

 the mile, or even the half of it. Such land 

 has not commonly a fall of even 20 feet to 

 the mile. If the assertion were then correct, 

 a vast quantity of such land must for ever lay 

 an irreclaimable morass. The assertion will, 

 indeed, be news to engineers and canal com- 

 panies, and if true, good news, too. They 

 generally find, and often much to their an- 

 noyance, that a fall of much less than one 

 foot to the mile will very effectually carry 

 ofi' the water from their reaches of canal, 

 when the lower wickets are opened and the 

 upper ones closed. 



