V 
 
 UNIVERSITY OF CALIFORNIA. 
 
 FROM THE LIBRARY OF 
 
 ,_DR. JOSEPH 
 
 GIFT OF MRS. LECONTE. 
 
 ' No. 
 
M. BUTT HEWSON, C. E. WILLIAM HEWSOJT, C. E. 
 
 MESSRS. M. BUTT HEWSON AND BROTHER, CIVIL ENGINEERS. 
 
 HELENA, ARKANSAS. 
 
 The Messrs. Hewson offer their services as Civil Engineers to Railway 
 Companies, Levee Commissioners, Bridge Companies, and all other 
 parties engaged in the direction or execution of Public Works. Designs, 
 Plans, Surveys, Specifications, Estimates, Measurements, &c., made for 
 all descriptions of Engineering work. 
 
 Letters addressed as above, will be attended to with promptness. 
 
PRINCIPLES AND PRACTICE 
 
 OF 
 
 EMBANKING LANDS 
 
 FROM RIVER-FLOODS, 
 
 AS APPLIED TO 
 
 "LEVEES" OF THE MISSISSIPPI. 
 
 BY 
 
 WILLIAM HEWSON, CIVIL ENGINEER ; 
 
 ASSISTED IN TUB ENGINEERING REMARKS BY CONSULTATION WITH M. BUTT 
 
 HEWSON, ESQ., CIVIL ENGINEER, LATE CHIEF ENGINEER OF THE CENTRAL 
 
 RAILROAD OF MISSISSIPPI. &C., 4C., &C. 
 
 NEW YORK : 
 
 JOHN J. REED, PUBLISHER, 
 43 & 45 CENTRE STREET. 
 
 1059. 
 
Entered, according to Act of Congress, in the year 1858, by 
 WILLIAM HEWSON, 
 
 In the Clerk's Office of the District Court of the United States, for the Southern 
 District of New York. 
 
 J. J. REED, PRINTER & STEREOTYPER, 
 43 Centre Street, JS T . Y 
 
T O 
 
 THE HONORABLE JAMES L. ALCORN, 
 
 CHAIRMAN 
 
 OF THE SUPERIOR BOARD OF 
 
 LEVEE COMMISSIONERS FOR THE STATE OF MISSISSIPPI, 
 
 &c., &c., &c., 
 
 THIS WOKK IS DEDICATED 
 
 BY HIS FRIEND, 
 
 WILLIAM HEWSON. 
 
 2G5 
 
NEW YORK, SEP. 15th, 1858. 
 
 To the Hon. James L. Alcorn, } 
 
 Of Mound Place, Coahoma County, > 
 
 MISSISSIPPI. ) 
 
 MY DEAR SIR : 
 
 As father of the Levee-system, in at least that State, you are, 
 on public grounds, the man of all others to whom ought to be 
 dedicated the following results of my reflections and labors on 
 the Levees of Mississippi. As a Legislator, as a County 
 Commissioner, as a general Commissioner, for the conduct of 
 those improvements, your zeal, energy, and talent, have con- 
 tributed, in an eminent degree, to the present matured 
 prospects of the most important material interests of your 
 State the drainage and reclamation of the great Valley of 
 the Yazoo. As an agent, under your direction, in the accom- 
 plishment of that great result, I am bound, therefore, to lay at 
 your feet this summary of the views and rules by which I have 
 been guided in that agency. 
 
 As a private friend, however, you of all my friends in this 
 country, have the first claim on my feelings. Truthful, warm, 
 and disinterested, as I have ever found you in our long and 
 somewhat trying intercourse, it affords me cordial pleasure to 
 give public evidence, by even the dedication of this vol- 
 ume to you, of my profound conviction of your truth, warmth, 
 and disinterestedness as a private friend. 
 
 While your qualities of head in the capacity, the courage, 
 
6 
 
 the integrity, with which you have managed the public inter- 
 ests committed to your care command my unqualified 
 respect, it is privately a pleasure to me as publicly it is a 
 duty to inscribe to you, as I here do, this result of my expe- 
 rience and reflection on River-embankment. Accept it, my 
 dear Colonel, as an humble expression of the honest regard of 
 your ever faithful friend, 
 
 WILLIAM HEWSON. 
 
 P. S. Two years ago, this volume was commenced ; though 
 in the intervals of leisure occurring under active engagements 
 of my mind, it had not been completed until to-day. 
 
PREFACE, 
 
 IMMENSE public wealth is being- accumulated behind 
 the Levees of the Mississippi. From Cairo to the Balize, 
 millions of acres of the finest land in the world are being 
 reclaimed from the Bear and the Panther, to bring* forth 
 fruit for the enrichment of the American Union, and the 
 luxury of private industry. Millions of money have 
 already been expended on the works, behind which this 
 great investment of enterprise of labor and capital is 
 going on ; and yet. up to the present hour, these expendi- 
 tures have been made, to a great extent, without regard 
 to the teachings of a regularly digested experience. This 
 book devoted to the Levee, and to Levee interest is, 
 therefore, given to the public, the first attempt to reduce 
 to order and to rule, the design, execution, and measure- 
 ment of the Levees of the Mississippi. Hundreds of 
 thousands of people are concerned to the extent of their 
 fortunes if not, even of their lives in the subject treat- 
 ed of here ; and hence is it unnecessary for the author to 
 
8 PREFACE. 
 
 apologize to the public, for an attempt to reduce a 
 subject of such immense importance to an exact popular 
 rationale. 
 
 The necessities of a country so new as that along- the 
 Mississippi, place the management of its public works in 
 the hands of unskilled men. This fact, coupled with 
 others proper to the case, commits the execution of the 
 Mississippi Levees to the inexperienced good sense of 
 the planter, or, less safe guide, to the inexperienced 
 manipulations of the laborer, the wood-chopper, the me- 
 chanic, who succeeds in obtaining from that planter 
 employment as a Civil Engineer. This condition of 
 things, is, under all the circumstances of the case, to 
 some extent unavoidable; and in order, therefore, to 
 make it comport as far as possible with the proper man- 
 agement of the Levees, this summaiy of the principles 
 and practice of Leveeing, is made in terms equally intel- 
 ligible to the professional short-comings of those " En- 
 gineers," and to the popular knowledge of those 
 planters. 
 
 Those gentlemen who, engaged on the Mississippi 
 Levees are, in fact, Civil Engineers, will doubtless 
 receive this humble volume favorably. They will, it is 
 hoped, find something in it that may assist their labors 
 directly, and much that will tend to strengthen their 
 influence over the works, by convincing the intelligent 
 planter, that those works are subjects of extensive reflec- 
 tion and experiment in a certain department of know- 
 ledge. 
 
 This Memoir, humble as it is in its pretensions, will 
 do good service to the profession, and to the public, if it 
 
PREFACE. 9 
 
 assist the parties interested in Levees to discriminate 
 between the educated Engineer and the untrained pre- 
 tender. 
 
 This volume contains a short review of the History of 
 Embankments. Natural Phenomena of Rivers have also 
 been considered in it briefly, especially those phenomena 
 bearing- more directly on the theory of Leveeing. The 
 Engineer and Levee Commissioner will find these heads 
 of some value for their own guidance, and also, in obtain- 
 ing that co-operation for their plans, which must always 
 follow from enlightening, on the subject of those plans, 
 the population living behind the Levees. 
 
 The principles of Economy and Usefulness, touched on 
 in this part of the subject, will be of great importance to 
 the Engineer and to the Commissioner, in indicating use- 
 ful reforms in the present system of Levee management 
 and construction. 
 
 The Earth-work tables included in the following pages, 
 will be found of general interest. They embody a new 
 system of obtaining, by inspection, the areas of Earth- 
 works in exact accordance with the prismoidal formula. 
 They are alike applicable, as far as they extend, to the 
 prisms of the Levee-bank, the Canal-bank or cut, the 
 bank or cut of the Railroad. For slopes of a varying 
 rate, or of greater extent than those given in the tables, 
 the plan pursued in the preparation of those tables is 
 equally applicable ; and is, therefore, highly valuable to 
 the practical Engineer, as a means of -simplifying to an 
 extraordinary extent, the laborious reference necessary 
 in such tables as Sir John McNeill's, for calculating quan- 
 tities by the prismoidal formula. 
 
10 PKEFACE. 
 
 The Contractor on Levees is highly interested in the 
 publication of the Earth-work tables included in these 
 pages. Ignorance and carelessness have, too generally, 
 characterized estimates of the quantities of Earth-work 
 executed in Leveeing ; the consequence being, some- 
 times, large losses to the contractor, sometimes large 
 losses to the public. These tables, placing the facts 
 within the reach of both parties, guarantee, therefore, 
 justice in all cases to each. The use of the tables as 
 explained in the letter-press, is short and simple. Men 
 of ordinary intelligence, knowing the heights of a Levee, 
 at intervals of 100 feet, can tell with accuracy by those 
 tables the solid content of the Levee. The Commissioner, 
 the Engineer, the Contractor, and the Public, can, there- 
 fore, bring these results within the compass of the popu- 
 lar knowledge. 
 
CONTENTS. 11 
 
 CONTENTS. 
 
 CHAPTER I. 
 SKETCH OF THE HISTORY OF EMBANKING, 13 
 
 CHAPTER II. 
 NATURAL PHENOMENA OF RIVERS, ...... 22 
 
 CHAPTER III. 
 
 THE LEVEE, 53 
 
 CHAPTER IV. 
 
 DETAILS OF LEVEE WORKS, . 79 
 
 CHAPTER V. 
 
 HIGH WATER MARK, 102 
 
 CHAPTER VI. 
 
 LOCATION, 106 
 
 CHAPTER VII. 
 
 SURVEYS, ' 116 
 
 CHAPTER VIII. 
 ADMINISTRATION, 121 
 
 CHAPTER IX. 
 EARTH-WORK CALCULATIONS, 134 
 
 THE TABLES . 153 
 
PRINCIPLES AND PRACTICE 
 
 OF 
 
 EMBANKING LANDS FROM RIVER-FLOODS. 
 
 CHAPTER I. 
 
 SKETCH OF THE HISTORY OP EMBANKING. 
 
 " LEVEEING " Embanking as it is generally called to confine 
 rivers within their banks, and bar the approach of the sea, and 
 its sister system of back-drainage, have, from a very early 
 period, occupied the attention of individuals, governments and 
 peoples. 
 
 The Phcenecians, Babylonians, Egyptians, Eomans, Hindoo- 
 stanees, and other East Indian nations, embanked low lands and 
 drained marshes. Those nations chiefly inhabited alluvial 
 plains, which, by their superior richness of soil when reclaimed, 
 amply repaid them in the abundance of their crops, at less 
 labor than was necessary to expend in the cultivation of higher 
 districts. History informs us that the Babylonians and Egypt- 
 ians were the first to adopt the system of reclaiming waste 
 lands by embankments. 
 
 The low ground in the midst of which the city of Babylon 
 was built, affords an early instance of the necessity of embank- 
 ing ; and consequently taught its inhabitants the principles of 
 construction in earth works. The causeway thrown up over the 
 
14 PKINCIPLES AND PRACTICE OP 
 
 low grounds, on each side of the Euphrates, leading to the cel- 
 ebrated bridge over that river, is the most remarkable, because 
 it is the most ancient, of which there is any record. 
 
 Egypt, the land of floods and marshes, from the richness of 
 its soil when reclaimed, was enabled at known periods of his- 
 tory to supply during times of dearth the impoverished nations 
 around with corn. Egypt, when subject to Rome, was the 
 granary from whence supplies for that city were drawn. About 
 2320 years before the Christian era, the greater part of Egypt 
 was an extensive marsh, which Men6s, the then-reigning 
 King, undertook to reclaim. He diverted the course of the 
 Nile into the middle of its valley or " bottom lands ;" cut water- 
 courses and raised embankments to confine the waters within 
 them. His successors, each in his turn, made similar improve- 
 ments raised mounds on which to build their cities, above 
 overflow, and cut canals for irrigation. The celebrated Lake 
 Mceris is represented as one of the most remarkable works of 
 ancient Eygpt ; and is supposed to have been executed by a King 
 of that name ; and finished about 1385 years B. C. This Lake was 
 according to Herodotus 450 miles in circumference, and is said 
 by some to have been in places 300 feet deep. * By means of 
 
 * This summary of the great drainage works of the past follows without question 
 the statements of History. Here, however, it may be observed that this Lake Mceris 
 story seems to be one of the most preposterous inventions of even Herodotus. The 
 pumping necessary to keep such an excavation dry is with even all the appliances 
 of steam an inconceivable feat. The lifting and moving performances of the ancient 
 Egyptians are truly wonderful, but how they could have hauled the infinite volume 
 of excavation from such a "pit" as Lake Mceris, with an average haul of some 30 
 miles is beyond all comprehension. Waiving, however, these difficulties, the story is 
 absurd. At an average depth of 150 feet^-one-half the aUeged maximum depth 
 the earth moved from Moeris would represent a content of 2,400,000 millions of cubic 
 yards. Supposing the Egyptians furnished with the improved tools of modern ex- 
 cavations, this work at the rate of 5000 cubic yards per man per year, would have 
 consumed for "loosening and lifting" the labor for 12 months of 480 millions of men. 
 Done as stated in the reign of King Moeris, if it be supposed that he reigned for even 
 
EMBANKING LANDS FEOM RIVER-FLOODS. 15 
 
 a canal it was supplied with water for six months in the year 
 this water during the remaining six months returning to the 
 river by a regular system of irrigation throughout the whole 
 extent of Egypt ; thus supplying the land with moisture during 
 the dry season. This Moeris Canal, in itself a stupendous 
 effort of art, is still entire. It is 40 leagues in length. There 
 were two others also in connection with the lake having sluices 
 which were shut and opened alternately as the waters of the 
 Nile varied in elevation. 
 
 The ancient Romans were more remarkable for the extent of 
 their embankments, and the energy and skill put forth for the 
 reclamation of submerged lands, than any other nation before 
 their time. They appear to have been the special guardians 
 of the swamps and marshes of Europe. The inducements to 
 this guardianship lay in the great superiority and richness of 
 those soils as compared with the more elevated districts. 
 
 The Romans embanked the Tiber near Rome, and confined 
 the waters of the Po in a similar manner for many miles from 
 its embouchure. Remains of their embankments are to be 
 found in Holland, in most of the Fen-districts of England, and 
 in other countries where their indomitable energy and perse- 
 verance carried them. 
 
 India presented originally great difficulties to culture. Its 
 physical and its atmospheric character combine to present for- 
 midable draw-backs to natural production. Consisting largely 
 of alluvial flats, the suddenness of its monsoon-rains, the short 
 duration of those rains, and the long duration of the succeed- 
 ing drought, place cultivation completely subject to these two 
 conditions irrigation at one season of the year, and drainage 
 at another. Embankment is the prime means by which these 
 
 48 years, the work must have employed for that period in digging alone 10,000,000 
 of able bodied laborers ! 50 millions of people must therefore have lived on the works, 
 and a like number have been employed feeding them. 
 
16 PRINCIPLES AND PRACTICE OF 
 
 have been accomplished ; and these embankments, or, as they 
 are called in Hindostan, " Bunds," are the great artificial agents 
 that have conferred the teeming luxuriance of the present 
 state of that country on the soil of India. The " Bunds" of 
 India, while damming back the flools of the monsoons from the 
 rich flats behind them, run in double lines ; and by confining 
 between them the waters of those floods, reticulate Hindostan 
 with numberless canals. Naturally, these waters would escape 
 at periods of overflow, through a few rivers ; but, distri- 
 buted through numerous canals, they are retained on their 
 passage to the sea sufficiently long to answer through the dry 
 season the purposes of irrigation. To husband the too-copious 
 monsoon-rains, the natives have built " Bunds" of great magni- 
 tude across river-vallies and streams, thus forming artificial 
 lakes or reservoirs, often of vast extent, as storehouses, to 
 supply the wants of a dry season. From these the water is 
 conducted for miles along the flanks of mountains, across 
 gorges ' and vallies, and through the most difficult countries, 
 irrigating the land in its descent. Taught by the necessities 
 of their country, the East Indian nations of by-gone ages have 
 left behind them the remains of works of irrigation monu- 
 ments of their greatness unsurpassed even by Egypt. One 
 of these on the Island of Ceylon, an evidence of the enterprise 
 and public spirit of the Cinghalese monarchs, is a good speci- 
 men of such works. It was formed of huge blocks of stone, 
 strongly cemented together and covered over with turf, a solid 
 barrier fifteen miles in length, one hundred feet wide at base, 
 sloping to a top width of 40 feet, and extending across the 
 lower end of a spacious valley. 
 
 Egypt was undoubtedly the cradle of the sciences, and par- 
 ticularly Hydraulics. It remained, however, for later times to 
 arrange the laws of fluids into well defined formula. This 
 science seemed to lay dormant for many hundred years ; and 
 
17 
 
 it was not until during the eleventh and twelfth centuries, when 
 it was thought necessary to make several of the Italian rivers 
 navigable, and to cut canals for drainage and irrigation, and in 
 the thirteenth century x ,when the practice of embanking and 
 confining the rivers of Italy within their banks, was adopted, 
 that it can be said to have claimed the attention of the learned. 
 Before the seventeenth century there was scarcely any 
 known digest of principles, by which, to carry out the works 
 of the Hydraulic Engineer. 
 
 In the year 1665, a Congress of the most celebrated scien- 
 tific men met in Tuscany. At this Congress it was proposed 
 by Cassini and Yiviana, to confine the Chiana by banks, and 
 so conduct it to the Arno. During a subsequent meeting, at 
 which Torricelli was present, the embankment of the Chiana 
 was recommended on the ground that the rivers Arno, Tiber, 
 and Po, were confined by the same means. At this period, 
 practical Hydrodynamics received a great impetus ; congres- 
 sional meetings of scientific men were held, which, under the 
 necessity of reclaiming all the submerged lands of Italy, called 
 out the energies and talents of a host of the ablest philoso- 
 phers of the age. The experience, experiments and writings, 
 brought forth under these circumstances laid the foundation 
 of our knowledge of Hydraulics in nearly all its branches. 
 Amongst the distinguished men contributing at that time to 
 this subject, were Gallileo, Torricelli, Guglielmmi, Poleni, 
 Manfredi, Zendrini. 
 
 A general system of embanking rivers, as a consequence of 
 this movement amongst the savans of the day, was adopted in 
 Italy, so that the Po, Adige, Tiber, Arno, Reno, and their 
 tributaries are now confined between high, artificial banks. 
 
 Italy, from the peculiarity of its physical character, seems 
 adapted by nature for the cultivation of this science. Lofty 
 mountains, frequent rain-falls, heavy snow-drifts, break the 
 
18 PRINCIPLES AND PRACTICE OF 
 
 region of the Alps and Appenines into, frequently, foaming 
 torrents, torrents that, descending with headlong impetuosity 
 to the more level country on the sea-board, pour destruction 
 upon town and field. Along the low lands of the Po, perhaps 
 the most fertile section of all northern Italy, from the destruc- 
 tive character of its precipitous floods, immense changes have 
 taken place from time to time. The river has frequently 
 changed its course, filling lakes and marshes, destroying towns, 
 and causing immense devastations. Hydraulic Engineering 
 has executed its first systematic works on the drainage of the 
 Po ; and the nations of modern Europe have received there- 
 from, knowledge which enabled them to carry on similar works. 
 France, Spain, Holland, Germany, England and Ireland, are 
 thus alike indebted in this department of practical science to 
 Northern Italy. And, now, embankments which reclaim im- 
 mense bodies of rich land abound throughout all Europe. 
 
 Holland is well known to be low and flat. The alluvial de- 
 posits brought down, before even the dawn of History, from 
 the higher districts of Western Germany and Northern France, 
 by the Scheldt, the Meuse, and the Rhine, resulted in a marine 
 swamp, known now as the "Low Countries." This once salt- 
 marsh has been erected into the rich and prosperous Kingdom 
 of Holland by "Dikes" or embankments. De Luck, in the first 
 volume of his Geological Travels, says, " that the sea banks on 
 the coast of the North sea, at the mouths of the Eyder and Elbe, 
 extend to not less than 350 miles." And by another author, 
 " the Southern shore of the North sea is embanked to the ex- 
 tent of 600 miles, the Southern shore of the Baltic for 1000 
 miles, and the Bay of Biscay to the extent of 300 miles." All 
 the great rivers of Germany and Holland, such as the Rhine, 
 the Elbe, the Oder, the Leek, the Yaert, the Yssel, the 
 Maes, have all been confined to their channels by embank- 
 ments. 
 
EMBANKING LANDS FROM RIVER-FLOODS. 19 
 
 The Zealand Dikes or embankments are said to be at least 
 300 miles in extent, and to cost for annual repairs, the large 
 sum of $800,000 ! The sum expended for similar objects and 
 for the regulation of the Vater-levels throughout Holland alone, 
 amounts to $3,000,000 per annum ! The early history of 
 embanking in Holland, Zealand, and other places, presents a 
 series of calamities from the destructive power of water, 
 almost unparalleled in history. 
 
 England is probably indebted to the Romans for the first 
 embankments on the Thames. " London" indicates by its 
 derivation from the Saxon words " Lyn din," that it was once 
 " the City of the Lake." And history tells us that it owes its 
 existence to the drainage of its site ]by embankments. The 
 fact, however, may be settled without an appeal to history. It 
 is well known that many of the marshes in the immediate 
 vicinity of London now tinder consideration, as subjects for 
 embankment, are 12 feet below high tide in the Thames. The 
 original marshy character of the ground on which the modern 
 Babylon like the ancient Babylon stands, is indicated also 
 by the fact, that many of its streets terminate with the word 
 " Wall ;" the names of several towns and places, such as Black- 
 wall, Mill-wall, &c., on the Thames, are compounds of the same 
 word, which in Kent, and Essex, is, to this day, the popular 
 name for embankment. It is stated in an article published in 
 the " Builder" of 22d August, 1857, headed, " Two Aspects of 
 London ;" that " All the space which is now so thickly covered 
 with vast works, and occupied with living multitudes, was a 
 watery waste, as desolate as the neighborhood of Babylon at 
 the present day. Standing on a high part of Clerkenwell, or 
 Islington, it is easy to imagine the picture ; a foreground of 
 sedges, reeds, and willows. On the South East and West, a 
 space of water extends to the base of the high-lands, present- 
 ing the appearance of a large lake in which the channel of the 
 Thames is not even defined 1" 
 
20 
 
 PRINCIPLES AND PEACTICE OP 
 
 The commencement of modern embankments in England, 
 took place under Cromwell, about the middle of the 17th 
 century. In 1478, however, the works undertaken by Bishop 
 Morton, and subsequently completed by Charles the First, 
 conjointly with the Earl of Bedford, and his friends, reclaimed 
 1,033,360 acres of rich land. In the space of a few years, 
 previously to the year 1651, about 425,000 acres of fens, 
 morasses, or overflowed lands, were recovered in Lincolnshire, 
 Cambridgeshire, Hampshire, and Kent. Through the exer- 
 tions of Sir Cornelius Yermuyden a Zealander, who confined 
 the Welland, and the Ouse within artificial embankments, a 
 district has been reclaimed from the sea, in England, larger 
 than the whole Kingdom of Holland. Sir John Eennie, in 
 conjunction with Mr. Telford, constructed the celebrated Nene- 
 outfall, which, with the aid of banks, drained immense bodies 
 of rich land. Mr. Wiggins says, that " the embankments on 
 the coast of Essex alone, measure 220 miles." The principal 
 rivers in England, subject to heavy freshets, are all embanked, 
 the Thames, the Mersey, &c. 
 
 Of late years, embanking overflowed lands has been carried 
 on extensively in Ireland ; and in connection with the drain- 
 age of those lands by deepening the beds of the principal 
 rivers and their tributaries, has been done almost exclu- 
 sively by the Government, at the expense of the owners of the 
 improved lands. 
 
 This summary of the historical facts of embanking is required, 
 by the conciseness necessary in presenting the subject here, 
 to be thus brief and general. Dugdale's history of embank- 
 ing an English work of great merit, will furnish the curious 
 with the details of this great head of National industry ; but 
 sufficient has been here said, to indicate the extent to which 
 the subject of Leveeing may be considered within the pale 
 of practical science, and extensive practical experience. 
 
. 
 EMBANKING LANDS FROM RIVER-FLOODS. 21 
 
 Individual observation however extended will not, there- 
 fore, be brought by really intelligent men into conflict with 
 the teachings of a knowledge contributed to by so many 
 distinguished men, and tested by so many centuries of actual 
 practice. 
 
22 PRINCIPLES AND PRACTICE OF 
 
 CHAPTER II. 
 
 THE NATURAL PHENOMENA OF RIVERS. 
 
 LEVEES on the Mississippi are both important and costly. 
 Works involving so much public and private interest, and so 
 much public and private outlay, ought to be predicated on 
 principle. To oppose the laws governing a mighty river, is a 
 labor from which even the Hercules of American energy may 
 well recoil, and therefore does it become a duty of common 
 sense to place that energy, in dealing with the Mississippi, at 
 a labor in the least possible discord with those laws. To do 
 this, it becomes necessary in the first place, to study the habits 
 of rivers generally, and of the Mississippi particularly when 
 its habits are separated from those other rivers by specialities. 
 The particular habits of the Mississippi may be made subjects 
 of local observations ; but in order to confine the sphere of 
 those observations to its proper limits, and to assist in its in- 
 ferences, it is necessary to consider here in popular terms, the 
 general rules affecting the regime of rivers as applied specially 
 to the Mississippi. 
 
 Science is acquainted but generally with the causes by which 
 river phenomena are influenced or the complicated laws by 
 which they are governed. The little success that has attended 
 the labors and reflections of enquirers on this subject from the 
 time of Gallileo, is attributable to the difficulty of making cor- 
 rect observations, and to the local specialities which exist in 
 most rivers. The following review contains a summary of the 
 exact laws, and approximate rules deduced from observations 
 of rivers. 
 
EMBANKING LANDS FROM EIVER-FLOODS. 23 
 
 The surface of a country may be generalized into a series of 
 inclined planes those planes ascending from the sea-level 
 at the shore, to the mountain-heights of the interior. In a 
 paper drawn up for the Institute of Civil Engineers by Mr. M. 
 Butt Hewson, explanatory of the system pursued by him in 
 carrying out certain works for the Board of Public Works in 
 Ireland, the hydrographical distributions of rain-shed are thus 
 indicated : " The surface of a country is resolved by its 
 drainage-waters into several systems of vallies. These vallies 
 are termed by Engineer's rain or " catchment " basins. The line 
 of lowest level in each of these is traced by a stream this 
 stream tends to its debouching point, more or less tortuously, 
 more or less inclined. A catchment-basin is generally resolv- 
 able into several minor vallies associated together by the direct 
 discharge of their respective streams into one common outlet ; 
 the several points of this discharge marking the several stages 
 of increase in the area of the basin. A- great central valley 
 traverses the lowest level of these river-basins, secondary vallies 
 branching from each side of this, constituting in their turn 
 central vallies to distinct portions of the whole catchment. 
 Tertiary vallies so to speak branch again from these second- 
 ary vallies, and like those secondaries, become so many distinct 
 trunks to so many distinct systems of branch vallies. And so 
 on until the sources of mighty rivers are traced on all sides of 
 their basins, into the ravines of far off ridges, and the gorges of 
 snow-capped mountains." The physical features of a country 
 being of this character, the fact of rain-falls results necessarily 
 in the facts of Cascade, Rapid, Stream, Rivulet, and River. 
 Drawn up by that great mechanical agent, Heat evaporating 
 water from the surface of the earth and of the sea water-laden 
 clouds, driven and distributed by the winds, are by various 
 causes precipitated on the land ; and bursting over any portion 
 of a country their waters are congregated by gravity from the 
 higher into the lower vallies, and collecting strength as they 
 
f PRINCIPLES AND PRACTICE OF 
 
 rush down their several inclined planes, push forward in their 
 downward course, over cataracts, down rapids, through lakes, 
 and gently sloping streams, till uniting in one common grand 
 volume in the primary valley, they roll forward to the sea, in 
 the power and magnificence of a Mississippi, an Amazon, a 
 Ganges, or a Nile. The amount of water thus falling upon the 
 earth is not less than thirteen hundred millions of gallons per 
 second throughout the year ; one-half of this quantity is be- 
 lieved to run off the surface of the earth directly in rivers, 
 which is the cause of floods, one-fourth is evaporated and taken 
 up by vegetation, and the remaining fourth passes into the 
 earth, keeping up a constant supply to the numerous springs 
 which, to a great extent, feed and preserve the summer flow 
 of water-courses. 
 
 Large and small rivers are governed by the same laws, under 
 the same circumstances. The smallest rivulet has its own 
 catchment-basin, or fain-shed, corrodes the bank that confines 
 it, and pushes forward towards the sea, in proportion to its 
 strength, the matter thus detached and held in mechanical 
 suspension by the rushing of its waters. This smallest rivulet 
 is characterised by its overflows, its sand-bars, eddies, sinuosi- 
 ties, and siltings-up of bed along its course, and at its mouth, 
 in precisely the same manner as the great " father of waters," 
 or any of the other mighty water-courses of the earth. 
 
 The course of all rivers is so devious that the distance 
 between their extremities is very frequently twice the length 
 of their rectilinear distance. Every obstacle or projection in 
 the bank where the soil is harder and of a more resisting 
 nature, the slightest irregularities in the bottom and sides, 
 partially obstruct its course ; and according to the magnitude 
 of that projection, deflects, or tends to deflect, the current to 
 the other side. This deflection of the current produces a 
 circular motion in the water, which acting on the soft portions 
 of the bank, hollows it out, forms eddies, and accelerates 
 change in the direction of the current. 
 
EMBANKING LANDS FKOM EIVER-FLOODS. 25 
 
 Overflows or freshets, in rivers are very variable in volume. 
 They are dependent upon a variety of causes being brought 
 to bear to produce them. Heat and cold, clouds and winds, 
 forests and mountains, as first causes, are all intimately connect- 
 ed with their origin ; cultivated lands, dense forests, water- 
 bearing strata, and rocks of a permeable and of an impermeable 
 nature, as secondary causes, have each their respective 
 influence in passing off rapidly, or in passing off slowly through 
 springs, the waters falling upon them. The depth of rain-fall 
 varies greatly in different hydrographical districts, so that two 
 rivers with the same extent of rain-basin, may differ largely 
 in the amount of their maximum volume. Rain-shed is greater 
 in mountainous districts than in plains. It is greater in equa- 
 torial than in polar regions, and varies, even in the same 
 latitudes, to an extent often as great as that between Northern 
 and Southern districts ; for instance, it is greater in Ireland 
 than in Russia, and it is greater on the Western slopes of the 
 Cascade and Rocky mountains, than on their Eastern slopes. 
 The sudden melting of snow, or a continued rain-storm, will 
 sometimes congregate rapidly into a river channel an amount 
 of water equal to a high multiple of its average outflow. At 
 Marseilles, France, in a shower of rain of 14 hours duration, 
 thirteen inches have fallen, constituting a high proportion of 
 its rain-fall for twelve months ; and at London, England, six 
 inches have been known to fall in one and a half hours nearly 
 one-fourth its mean annual fall. And from the same cause, 
 Western rivers are seen occasionally to rise from 15 to 20 feet 
 in 24 hours ; and even a height of five feet, like a wall, is some- 
 times observed to come rolling down, sweeping all before it in 
 the descent. There are various causes in the river-bed, acting 
 to retard the flow of those waters, and helping by that retarda- 
 tion to raise their surface, such as friction, eddies, sinuosities, 
 and other circumstances. M. Yenturi deduces from his 
 experiments on tubes with enlarged parts, " That eddies 
 
26 PRINCIPLES AND PRACTICE OP 
 
 destroy part of the moving force of the current of the River, 
 of which the course is permanent, and the sections of the bed 
 unequal, the water continues more elevated than it would have 
 done, if the whole river had been equally contracted to the 
 dimensions of its smallest section, a consequence extremely 
 important in the theory of rivers, as the -retardation experi- 
 enced by the water is not only due to the friction over the 
 beds, but to the eddies produced from the irregularities in the 
 bed and the flexures and windings of its course, a part of the 
 current is thus employed to restore an equilibrium of motion 
 which the current itself continually deranges." The irregu- 
 larities of river-beds, and the irregularities of rain-falls are thus 
 seen to be combined in producing the phenomena of floods. 
 The irregularities of rain-fall are of course causes beyond 
 human influence, but the co-operating cause of floods the 
 peculiarities of river channels are within the field of human 
 operation, and become, therefore, the special object of enquiry 
 to the Engineer engaged in, and people affected by permanent 
 or periodic overflows. 
 
 All rivers decrease in their rate of descent as they approach 
 the outfall ; and this decrease is made over a series of curves 
 gradually flattening until they flow out into the tangent or 
 horizontal line of the sea-level. Short water-courses and 
 minor river-basins in mountainous districts are generally of a 
 precipitous character. Such are those of the Alps, and of the 
 Western slopes of the Rocky mountains. The large rivers 
 with which this continent abounds are generally for the greater 
 part of their length of slow descent. The average fall of the 
 Mississippi river for the whole distance from the gulf of Mexico 
 to the confluence of the Ohio, following the windings of the 
 river during low water, averages very nearly three inches per 
 mile. Supposing the channel of the river straight and the 
 rate of descent uniform between those points, the fall would 
 be about six inches per mile. But the actual rate of declivity 
 
EMBANKING LANDS FROM RIYER-FLOODS. 27 
 
 in a river is considerably increased in times of flood. Thus, 
 the Nile falling into a tideless sea, rises, at the city of Cairo 
 during floods, 25 feet, at Thebes, 36 feet, and at the first cat- 
 aract a point nearly equally distant from the mouth as Cairo 
 from the Balize about 40 feet. The Mississippi river falling 
 into a sea too of a very nearly constant elevation rises at 
 New Orleans 12 feet, at Friar's Point, Mississippi, 42J feet, and 
 at Cairo, Illinois, about 50 feet. This flood-rise at Cairo, added 
 to the elevation of low water at that point, gives an average 
 rate of fall for high water, following the windings of the river, 
 of three and a half inches, and on a direct line, of seven inches 
 per mile. There is, therefore, in the circuitous and in the 
 rectilinear distances a difference of fall equal to half an inch 
 and to one inch respectively per mile, due to the average rate 
 of fall during high water at Cairo, over and above that due to 
 the average rate of fall from the same point during low water. 
 A fixed expression has been deduced for the velocity of small 
 conduits. No formula for the purpose is yet found, nor is one 
 likely ever to be found, applicable to the infinitely varying 
 conditions of velocity in large rivers. Whatever may be the 
 co-efficients and the combinations necessary to give precise- 
 ness to any mathematical expression for river-flow, the terms 
 of that expression may be held, in general, to be the rate of 
 fall, the depth of volume, and the content of the sectional area 
 or friction-surface of the bed. Any change in either of those 
 three conditions, will all things else being equal involve a 
 change in the velocity of a river. Gravity being the motor in 
 all cases of water-flow, that flow would, unless under the influ- 
 ence of some retarding cause, take place, like the free fall of 
 any other body, with a constantly operating acceleration. 
 These retarding causes are more than one in the case of river- 
 flow ; they are represented by the loss of mechanical effect 
 arising from the shocks of the bank, and the friction of the 
 bed. The retardation arising from friction is one of constant 
 
28 PRINCIPLES AND PRACTICE OP 
 
 operation. The lower planes of the cross-section of river-flow 
 suffer more active retardation from this cause than the upper 
 planes ; the former being retarded by the friction of their 
 motion over the roughness of the bed, while the latter are 
 retarded by the greatly reduced friction of sliding over the 
 comparative smoothness of the lower water-planes. The deeper 
 the volume of a river, the higher therefore, is, not only its 
 surface velocity, but also, its mean velocity. And the same 
 remarks apply to the vertical planes of the volume ; the great- 
 est retardation taking place at the sides, the least in the centre 
 of the stream. The greater the width, therefore, the more 
 active so far as side-friction can effect the result is the flow. 
 But the friction of the sides is so small as compared with that 
 of the width, that the latter general deduction may be disre- 
 garded ; and we may conclude, practically, that an active 
 increase in the velocity of a stream a decided diminution in 
 the retardation of friction is always the result of an increase 
 of depth. 
 
 In even small streams a fall of one-tenth of an inch per mile 
 will produce a sensible flow. In large streams this rate of 
 inclination, would, as seen by the above reasoning, result in a 
 current proportionally more considerable. The frictional 
 resistance of a river-bed is higher for higher velocities than 
 for lower ; varying, according to the observations and deduc- 
 tions of M. Eytelwein, as the rate of the square of the velocity. 
 Such are the general facts of. fall and friction. 
 
 The effects of tributary waters, on the volume and velocity 
 of streams, appear somewhat paradoxical. Genn^tte, supported 
 by M. Eytelwein, asserts that one river may absorb another of 
 equal magnitude with itself, without producing a sensible 
 elevation of its surface. Cressy, in his Encyclopedia of Civil 
 Engineering, sustains this opinion by citing the absorption of 
 the Inn, by the Danube ; of the Mayne, by the Rhine ; of the 
 Sechio, by the Po, and of the Teverone, by the Tiber ; this 
 
EMBANKING LANDS FROM RIVER-FLOODS. 29 
 
 absorption, he states, taking place without making the volume 
 of the absorber in each case either deeper or wider. The only 
 effect of the accession to the body of water passing through 
 the main channel, in each . of the instances named, is said by 
 Cressy, to be an increase in the velocity. Guglielmini, in 
 evidence of the same opinion, refers to the accession of the 
 waters of the Ferrara, and Panaro, branches of the Po, to the 
 volume of that river without, as he alleges, producing any 
 sensible augmentation of its channel. 
 
 A corresponding increase of velocity must of course be 
 supposed a consequence of such an accession, if we are to accept 
 as a fact, that the accession of a tributary has no effect on the 
 width or the depth of its main out-fall. This increase of velocity 
 in the united volumes must, however, be referable to some com- 
 mensurate mechanical cause. The tributary volume, it is true, 
 discharges into the united volumes, the velocity proper to 
 itself ; and therefore, waiving the fact of altered rate of fall, 
 or of altered depth of flow, tKe united volumes may be held, on 
 mechanical grounds, to flow, after union, at a proportional 
 average of their respective velocities. That the union of the 
 two waters flows off without any increase in the original volume 
 of the main stream, were to suppose the result of their blend- 
 ing of mechanical effect, the sum, volume for volume, of their 
 original rates of flow. If the two volumes were, for example, 
 equal, the one moving originally at two miles an hour, the other 
 at three miles, then would the discharge of the united volumes, 
 without increase of width, or depth, or rate of descent, suppose 
 the resulting velocity to be Jive miles an hour. Mechanically 
 this is not supposable. Therefore, must we come to the 
 conclusion that it is impossible that the union of two rivers 
 can take place without an increase after the union, in either 
 width or depth. Eytelwein and Cressy must clearly have 
 either mistaken the fact or have stated it erroneously. 
 
 The conclusions of the respectable names given under this 
 
30 PRINCIPLES AND PRACTICE OP 
 
 head, are, like all conclusions, open to question. The facts, 
 however, must be received beyond all doubt. While there can 
 be no question as to the facts, that the Danube, the Rhine, the 
 Po, the Tiber, in all the instances of accession named, have not 
 been widened or devated ; the inference is irresistible, that in 
 all these instances, they must have been, to at least some 
 extent, deepened. The fact of deepening, resulting, as pre- 
 mised above, in a proportional diminution of frictional 
 resistance to flow, involves directly an increase in the rate of 
 flow. This, combined with the mechanical impulse of the 
 tributary volume, must, by accelerating the velocity, make the 
 increase of depth proportionally less than the increase of 
 accession. 
 
 It has been remarked by several writers that the width of 
 the Mississippi below the junction with the Ohio, is less than its 
 width above the junction. This is not only true of the river 
 in the case of the accession of the Ohio, but also, of all acces- 
 sions below that, and indeed, of the channel generally from 
 Cairo to the Balize. At Cairo, the Mississippi is upwards of 
 a mile wide ; at New Orleans, the width is but half a mile. 
 But this narrowing down-stream is accompanied by a corres- 
 ponding deepening a truth that is established popularly by 
 the fact that the higher a steam-boat goes up stream, in low 
 water, the more difficult is the navigation ; until, at Cairo, 
 further navigation at such times becomes almost impossible, 
 even for the smallest craft. 
 
 A rough approximation of the sectional areas, in times of 
 flood, of the Mississippi, at Cairo, and at New Orleans, in con- 
 junction with a like statement of all its intermediate tributary 
 streams, will be found on the next page. 
 
 An accession of some 500,000 square feet of tributaries is seen, 
 by this statement, to be passed through the Mississippi river at 
 New Orleans with an increase of volume over that at Cairo, of 
 but 160,000 square feet ; and through a channel upwards of 
 twi *- - n " d but one-half the width. 
 
EMBANKING LANDS FROM RIVER-FLOODS. 31 
 
 At Cairo, the sectional area of the Mississippi, is about, - 325,000 feet. 
 
 Of the Ohio, at junction, the sectional area is about, - 260,000 feet. 
 
 Of the St. Francis, at junction, do. - - 21,000 feet. 
 
 Of White River, at do. do. - - - 28,000 feet. 
 
 Of Arkansas, at do. do. - - 56,000 feet. 
 
 Of Yazoo, at do. do. - - - 21,000 feet. 
 
 Of Big Black, at do. do. - 21,000 feet. 
 
 Of Red River, at do. do. - - - 52,000 feet. 
 
 Of other tributaries, at do. do. - - 18,000 feet. 
 
 Total, - - 802,000 feet. 
 Of the Mississippi, at New Orleans, - 480,000 feet. 
 
 This fact, ascertained loosely as it is, establishes the correctness 
 of the general conclusion reasoned to above, namely, that 
 while on the authority of the statements of Gennette, Eytel- 
 wein, Guglielmini, Cressy, we must accept the fact that 
 tributary accessions to the volume of a river do not widen, or 
 elevate their general level, all such accessions result in an 
 accelerated velocity, and an increased depth. As a practical 
 application of this conclusion in the case of the Mississippi river, 
 it may be, therefore, safely affirmed, that the retention of 
 flood-water in the channel by levees, like all tributary acces- 
 sions to its volume, while deepening the channel, and 
 increasing the velocity will not, as a direct consequence, 
 elevate the surface of the water. 
 
 The conclusion arrived at in the foregoing paragraph appears 
 on its face paradoxical. Paradoxical or not, it must be 
 observed that it is a conclusion drawn fairly, from undoubted 
 premises. It will be said, if the enclosure of swr/ace-flood-water 
 within the channel do not elevate the level of the river-flow, 
 how is it that the accession of any flood-water at all produces 
 that elevation ? The inference drawn above is not affected by 
 this question ; because, not declaring that there are no varia- 
 tions of river-level, it applies to only those circumstances 
 under which a tributary-flood is discharged into the river-chan- 
 nel at the period of a correspohding flood in that main channel. 
 
32 PRINCIPLES AND PRACTICE OF 
 
 from its own supplies. The conclusion arrived at is in truth 
 this : a glut of water in the Mississippi will not be increased 
 in level by the accession of other gluts, from the Ohio, Arkan- 
 sas, <fec. But if we are to suppose every accession of flood- 
 water an accession of height ; and that we begin with 
 over-flows of even 6 feet at the accession of the Missouri, of 
 6 feet additional at the accession of the Ohio, of 6 feet more 
 for all accessions of minor streams, of 6 feet more for the 
 accession of the Arkansas, of 6 feet more for the accession of 
 Red Eiver, the flood level at New Orleans assuming no 
 adaptation of channel as we go down-stream would be 30 feet 
 above the surface of the land ! But what, on the contrary, is 
 the fact ? The elevation of floods at New Orleans is alto- 
 gether but 12 feet above the low-water mark, which increasing 
 up-stream, it is in fact, at Cairo, 50 feet and this in the face of 
 all the accessions from Hatchees, St. Francis, White, Arkansas, 
 Yazoo, and Red River. 
 
 The direct agent of change in a river-course is the current. 
 On the banks this acts in two ways by friction, and by impact. 
 The greater the velocity the greater of course will be the 
 length of the rubbing body that, moving along the bed and 
 bank, constitute the friction. The friction, therefore, varies 
 with the velocity ; being twice as great for two miles as for 
 four miles. Friction, varying also, as the weight of the 
 rubbing body varies as the depth, being twice as great in a 
 depth of 40 feet, as in a depth of 20 feet. All sections of 
 channel are subject to this consequence of flow ; but the more 
 even and regular the section, the less the friction. In irregu- 
 lar and uneven sections the friction runs from friction proper 
 into impact. 
 
 Impact begins in channels where friction ends. A stream 
 flowing over a smooth, straight bed is resisted by only the 
 adhesion due to friction ; but over a rough, crooked bed is 
 resisted, in addition to this adhesion, by shocks to the regular- 
 
EMBANKING LANDS FROM RIVER-FLOODS. 33 
 
 ity of its flow, whether against shoals, bars, stumps, or bends. 
 This further resistance combines within it all those impedi- 
 ments involving impact ; and for whatever part of the 
 cross-section of the flow is engaged in this impact, varies as 
 the weight of that cross-section multiplied by the square of the 
 velocity. The weight, however, varies directly as the depth, 
 being twice as great for a depth of 50 feet, as for a depth of 
 25 feet ; and hence does a river become the most powerful 
 agent of change by impact, at periods of highest flood. The 
 velocity, too, increasing with the depth, shews again and in a 
 higher degree, why a river exerts its greatest energy, so far as 
 impact expresses that energy, at the period of its greatest 
 depth. For impact as measured by velocity increases as the 
 square of the velocity, being nine times as great for the same 
 impediment and the same depth, in a stream of six miles an 
 hour, as in a stream of two miles an hour. 
 
 The effects on river beds and banks from friction and impact, 
 cannot be given here more satisfactorily than in those general 
 elementary terms. No experiments that have come under my 
 knowledge, furnish a measure of the effects of friction and 
 impact, in the case of rivers, by practical examples. 
 
 Friction and impact, so far, have been touched on as agents 
 for excavating material. After this excavation, however, they 
 continue to act on the material excavated with their combined 
 forces. A lump of earth for example, being rubbed off by 
 friction or knocked off by impact in the channel, is taken up by 
 the water and impelled forward by the rubbing and the striking 
 of the flow. Small bodies, and bodies of a weight a little more 
 than water, are thus moved along by the stream in suspension ; 
 larger bodies of a weight considerably greater than water, 
 being, by the same power, rolled forward over the bottom. 
 This energy, this power of transportation of material within its 
 channel by a river, may be understood in relative terms by the 
 
 remark that it is the combined effort of friction and impact of 
 
 3 
 
34 PRINCIPLES AND PRACTICE OF 
 
 the rubbing of the planes of water that flow past that material 
 and of the striking of that part of the flow which it impedes. 
 Practical results, however, give this energy a plainer expression. 
 The following facts, ascertained after a series of careful experi- 
 ments by Dubuat, show clearly the absolute energy of several 
 velocities of rivers for the transport of materials loosened by 
 their currents, or otherwise deposited in their beds : 
 
 Clay fit for pottery removed by water flowing at the rate per second of 3* inches. 
 
 Fine sand removed by water flowing at the rate per second of 6J inches. 
 Gravel about the size of peas removed by water running at the rate per 
 
 second of __7j inches. 
 
 Gravel about the size of beans removed by water running at the rate per 
 
 second of - ' - - - 12| inches. 
 
 Shingle large gravel about one inch in diameter, removed by water 
 
 running at the rate per second of - - - - - - 25 inches. 
 
 Flints about the size of hen's eggs removed by water running at the rate 
 
 per second of--- -40 inches. 
 
 Broken stones removed by water at the rate per second of - - 48 inches. 
 
 Soft rocks begin to yield with a velocity per second of - - - 52 inches. 
 
 Rocks with distinct stratification begin to yield with velocity per second of 72 inches. 
 
 Hard compact rock begins to yield with a velocity per second of - 120 inches. 
 
 From this table it appears that the very moderate velocity of 
 950 feet per hour, is capable of moving clay ; of 1900 feet per 
 hour, capable of moving fine sand, and of half a mile an hour, 
 capable of moving coarse gravel. The carrying or propelling 
 power of a stream on bodies within it, is seen from the table to 
 increase with its velocity ; the materials capable of movement 
 in a current of 4 miles an hour, being incapable of motion at 3, 
 2, or 1 mile an hour. This fact leads to some of the most im- 
 portant changes in rivers as will be shown below. As no prac- 
 tical examples of the abrasive effects of a current have been 
 given above, it may be observed here, that those effects, result- 
 ing as they do from the same causes, which, certainly with an 
 energy less in degree, constitute the propelling power of cur- 
 rents, are presented in the facts of the above table relatively. 
 
EMBANKING LANDS FROM RIVER-FLOODS. 35 
 
 Impact and friction " washing away " or " caving in " the 
 material of a river channel, it has been seen that impact and 
 friction continue to act afterwards on the material so " washed " 
 or " caved," for its propulsion along the channel into the out- 
 flow or sea. It has also been shown that this propelling power 
 is greater or less as the velocity of the stream is greater or less. 
 Friction, it has too been premised, is greatest in its retardation 
 of flow at the bottom and at the sides, the rate of flow being 
 always greatest in the middle, and at the top of the stream, and 
 diminishing from that top and from that middle on either side, 
 until, at the bottom and at the sides, it becomes the least. This 
 consideration may be put in this shape : the velocity of a stream 
 is unequal at every point of its section. Now a mass of material 
 broken off or rubbed off by a current from the bed or bank is, 
 when so broken or rubbed off, placed free to move in a current 
 of a certain velocity. This velocity, let it be supposed, has 
 energy sufficient to propel that mass. Like all moving bodies, 
 the motion of this mass tends to follow a straight line in the 
 direction of the force acting on it. But at a sudden bend or 
 obstacle in the river the thread of the stream, acting on this 
 soft mass, may be supposed to be deflected at a large angle 
 with its original deflection. The mass, being heavier than the 
 corresponding thread, will be deflected from its original direction 
 at a smaller angle than the water ; and hence, will take its 
 place in a different part of the water-section. By irregularities 
 in the direction of the flow the bodies rolled along a river bed 
 are thus seen to be constantly shifted from one position in the 
 cross section to another position in that section ; and conse- 
 quently are seen to be shifted into velocities constantly changing. 
 Of bodies carried along by a stream and so light as to be held 
 at first in suspension, the constant action of gravity tends to 
 the depression of those bodies ; and thus, in urging them con- 
 stantly downwards, brings them in their dropping through 
 different depths, into different rates of flow. All material then, 
 
36 PKINCIPLES AND PKACTICE OF 
 
 whether large or small, light or heavy, are seen to be subject 
 in river channels, to constantly changing velocities j and hence, 
 the carrying power of rivers depending on velocity, all material 
 too heavy or too large to be moved by the smaller velocities of 
 the cross-section of the stream, when once shifted into a position 
 having any of those smaller velocities, sinking to the bottom, 
 becomes fixed. The lighter and smaller bodies rolling along 
 that part of the section where this material thus becomes fixed, 
 accumulate around it as a nucleus, and this process of fixing 
 heavier matter and retaining lighter matter, results in shoals, 
 bars, islands, and those deposits known on the Mississippi, as 
 " making banks." 
 
 The amount of material carried down-stream by a river, 
 varies, as has already been seen, with the velocity and volume 
 on one hand, and varies on the other hand, with the hardness 
 or softness, lightness or heaviness of the material composing 
 the" bed and bank. The quantity of solid matter borne for- 
 ward by the Ganges is estimated at 1-40 of its volume, the total 
 quantity of earth propelled per year by that river being esti- 
 mated at the almost incredible amount of about 315,000 million 
 cubic yards. The Rhine is estimated by Mr. Homer to propel 
 solid matter to the amount of 1-16000 of its volume. At New 
 Orleans the earthy matter propelled by the Mississippi is esti- 
 mated by Dr. Riddell, taking a mean annual average, at an 
 amount of 1-1700 of the volume of the flow. The Mississippi 
 is shown by the estimate of Sir C. Lyell to carry earth below 
 New Orleans to the amount per annum of 137,000,000 cubic 
 yards. 
 
 Of the whole material propelled by a stream, a proportion 
 has been seen to be precipitated from mechanical causes in the 
 form of shoals, bars, islands, "making banks," &c. The residue, 
 however, of this quantity of matter is carried forward to the 
 debouch ; and pushed for further propulsion into the outfall 
 stream, or partly for further removal, partly for permanent de- 
 
EMBANKING LANDS FROM RIVER-FLOODS. 37 
 
 posit impelled into the sea. This deposit of material by sea- 
 discharging rivers, is the cause of that general accompaniment 
 of a system of rivers the Delta. Constant in its operation, 
 this canse of the formation of Deltas would, under circum- 
 stances always the same, lead to the constant extension of those 
 Deltas. This extension, however, must be held under its gen- 
 eral circumstances to take place, as measured by its direct ad- 
 vance, at a rate constantly diminishing, until finally it shall 
 have reached its limit of direct advance. The trend of a 
 shore-line may, for instance, be supposed to place the debouch 
 of a river in dead water ; and this dead water, favoring the 
 precipitation of material, the earth propelled into it by the 
 river, produces, to a certain point, a constant direct advance of 
 that river's Delta. At this certain point, however, the Delta 
 may be supposed to have passed from the dead water of its 
 original formation, and to have become subject to the disturb- 
 ing influence of an active current. Direct advance at this 
 stage of its growth may be thus considered at an end. The 
 direction of the river-flow crossing the course of the sea-cur- 
 rent at an angle, the resulting direction of commingling and of 
 deposit, follows a bend increasing more or less rapidly, accord- 
 ing to the energy of the sea-current, as compared with that of 
 the river, until, finally, it shall have assumed the line of the 
 sea-current. Such, in general, are the causes and condition of 
 the growth of Deltas. They apply alike to the Deltas of the 
 Mississippi in this country of the Orinoco in South America j 
 of the Ganges, of the Irrawaddy, of the Indus, <fcc., in Asia ; 
 of the Nile, and of the Niger in Africa ; and of the Rhine, of 
 the Rhone, of the Po, of the Danube, &c., in Europe. 
 
 The rates of advance in Deltas, consequent as they are on 
 the varying causes affecting their formation, are variable for 
 different Deltas. 
 
 The Ganges and Burrumpooter, deliver into the Bay of 
 Bengal solid material to the enormous amount during the 
 
38 PRINCIPLES AND PRACTICE OF 
 
 flood season of 500 million cubic yards every twenty-four 
 hours. There is no information at hand, as to the rate of 
 growth of the Ganges-Burrumpooter Delta. The incomplete- 
 ness of the recorded facts of the rivers of the great Deltas of 
 the world, makes it impossible to deduce any general law an to 
 the rate of Delta growth in any particular case. In this place 
 may be added all that are at hand of the facts of Delta growth ; 
 and, indeed, perhaps this may, after all, be quite sufficient for 
 the practical purpose aimed at under this particular head. 
 The Delta of the Nile has advanced but two miles since the 
 time of Herodotus ; but small as the consequent rate of advance 
 is, it has now been ascertained to have altogether ceased. The 
 Po, and the Adige, discharging at the same point into the 
 Adriatic, have formed their joint-Delta since the time of the 
 birth of Our Saviour. One hundred miles in width, this Delta 
 has, up to the present time, advanced into the sea upwards of 
 20 miles. Sir C. Lyell, after comparing the present tongue of 
 land below New Orleans, with the map published by Charlevoix, 
 alleges that the Delta of the Mississippi River has not advanced 
 more than a mile in a century. Mr. Rogers, in his report to 
 the British Association on the Geology of North America, 
 says however, that, " as an example of the rate at which it is 
 growing, the old Balize erected at the mouth of the river, about 
 the year 1724, is now (1834) two miles above it. There waa 
 not at that time, the smallest appearance of the island on 
 which, 42 years after, Ulloa caused barracks to be erected for 
 the pilots, and which is now known as the new Balize. The 
 distance from the mouth of the river at which the chief deposit 
 of sediment usually takes place is about two miles ; when 
 these shoals accumulate sufficiently they form small islands, 
 which soon unite and reach the continent, and thus the Delta 
 
 increases." 
 
 In this statement of the growth of Deltas it must be observed 
 that the statement for that of the Nile and of the Mississippi, is 
 
EMBANKING LANDS FROM RIVER-FLOODS. 39 
 
 applicable to rivers unconfined by Levees. The Nile overflows 
 its banks without artificial restraint. The Mississippi, up to 
 the period of the observations referred to, had been but very 
 partially Leveed j and hence do those observations of Mr. Rogers 
 refer to a river without Levees. The facts of the growth of the 
 Delta of the Po-Adige are, however, since the sixteenth 
 century, those of a Delta formed by a river whose floods are 
 confined within artificial banks. The rate of advance of the 
 Delta of the Nile from the birth of History until now, has been 
 4 feet a year ; of the Mississippi from 1724 to 1834 has been 
 96 feet a year ; of the Po-Adige, for the period between the 
 beginning of the first and the beginning of the thirteenth cen- 
 tury, 22 feet a year ; for the next following 400 years the 
 advance has been 82 feet a year ; and for the 200 years next 
 after that, it has advanced at the rate of 229J feet. The present 
 Levee system of the Po had its origin in the 13th century, but 
 was incomplete until the commencement of the 17th century. 
 Since the beginning of the 17th century, however, the em- 
 bankments of the Po and Adige have been completed from end 
 to end. The unleveed period of the Po shows an annual rate 
 of advance in its Delta of 22 feet. But from the introduction 
 of the Levee-system on that river (taking the average during 
 the whole period of its progress.) the rate of advance of the Po- 
 Adige Delta ran up from 22 feet annually to 82 feet : and from 
 the completion of the Levee-system, taking the experience of 
 200 years, the advance of the Po-Adige Delta has run up from 
 82 feet annually to a yearly rate of 229 1 feet. The conclusion 
 then from the experience in the case of the Po is irresistible, 
 in the absence of any other especial cause, to account for such 
 an accelerated advance, that the confinement of the river Po 
 within embankments has caused its Delta to advance into the 
 sea with comparative rapidity. Levees therefore, may be held 
 to involve an accelerated rate of extension of a river-Delta. 
 The advance of its Delta exerts decided influence on the high- 
 
40 PRINCIPLES AND PEACTICE OF 
 
 water level of a river. The flood-height of the Mississippi, which 
 at New-Orleans has been stated already at 12 feet above low- 
 water, is at Friar's Point 42 J feet above low water, and at Cairo 
 is 50 feet. Every 3 inches of elevation at New Orleans repre- 
 sents therefore an elevation at Cairo of 12| inches. Now the 
 rate of fall from New Orleans to the sea is about 1J inches per 
 mile, and therefore an advance of the Mississippi Delta at an 
 accelerated rate based on the acceleration resulting from Levees 
 to the advance of the Po-Adige Delta would give by an exten- 
 sion in 100 years of 4| miles of Delta an additional elevation 
 of 6J inches to flood level at New Orleans, an additional eleva- 
 tion to that level at Friar's Point, of 23 inches, and at Cairo an 
 additional elevation of 27 inches. The relative height of high 
 water at any point on the Lower Po, in comparison with that 
 at any point on the Upper Po, is not conveniently obtainable ; 
 but assuming it the same as between that at New Orleans, and 
 that at the Balize on the Mississippi, the extension of the Po- 
 Adige Delta since the completion of the Po and Adige Levees 
 9 miles of extension must have occasioned, for the preservation 
 of the same rate of incline of outflow from Ferrara down 
 stream, as from New Orleans down stream, an elevation at 
 Ferrara of 13 inches. The elevation of the Po, however, at 
 Ferrara is measured not by inches but by feet ; and the increase 
 of this elevation since the completion of the Levees must, there- 
 fore, be referred to some other direct cause than the extraor- 
 dinary extension of the Delta. 
 
 The overflow of a river discharges a large proportion of its 
 earthy matter upon the land. The confinement of the River 
 within Levees confines this proportion of its earthy matter to 
 the channel. The immense amount of the material so added 
 to the work of the stream, may be inferred generally from the 
 fact that in the case of the Nile, it was distributed over Egypt 
 by overflow, and has caused the elevation of the whole surface 
 of the country since the Christian era, at an average rate per 
 
EMBANKING LANDS FROM RIVER-FLOODS. 41 
 
 hundred years of 4J inches. The greatness of the aggregate 
 mass of matter added to the original proportion in its volume 
 by the construction of Levees, may be inferred generally, by 
 the immense additions resulting from Levees to the growth of 
 Deltas. But the carrying power of a water-course, like all 
 other mechanical agencies, has its limit ; and when we see any 
 cause loading it beyond its previously established energy, we 
 may reasonably expect that a portion of its excessive work 
 will of necessity be left undone. The motive power of a river 
 acting up to its limit in the removal of matter from its source 
 to the sea, may be readily supposed under its insufficiency for 
 the removal of the extra matter accumulated within its Levees 
 to drop a portion of that matter into irregularities in its bed. 
 The matter so dropped may be supposed to accumulate in 
 layers, as every accession of material increases the weight of 
 matter to be moved, over and above the enorgy of the stream. 
 But these causes of deposit in the beds of rivers apply in the 
 surcharging of matter in streams whether Leveed or unleveed, 
 though from the retention of all the matter within the channel 
 by Levees, much more strikingly in the case of Levees. The 
 Nile illustrates the fact that unleveed rivers undergo a constant 
 elevation of their beds ; for while the matter deposited during 
 the overflows of that stream as already stated, has elevated the 
 surface of Egypt 4J inches per century, the matter deposited 
 within the bed of the river has elevated the level of that bed 
 at the same rate. The facts in this case are so well defined 
 that it may be well to place them here on record. At Dami- 
 etta, the Balize of the Nile, where the elevation of overflow 
 in the river is imperceptible, the elevation in the level of the 
 river-bed and river-bank is inappreciable. At Cairo, 120 miles 
 from the mouth, where the flood-level is 25 feet above low 
 water-mark, the elevation of the land and of the river-bed is, 
 since the Christian era, 5 feet 10 inches. At Thebes, JOO 
 miles from the mouth, where the flood-level is 36 feet above 
 
42 PRINCIPLES AND PRACTICE OP 
 
 the low water line, the land and the river-bed have been 
 elevated, since the birth of Our Saviour, 7 feet ; while at the 
 first Cataract, 100 miles higher up-stream, the level of the bed 
 and of the bank have been raised, since the same period, as 
 much as 9 feet. Assuming the same width of channel in the 
 Nile at Cairo, at Thebes, and at the first Cataract, and 
 assuming further the same amount of detritus carried off, vol- 
 ume for volume, by the overflow at each of those three places, 
 we may not be surprised to find that a 40 foot flood, giving an 
 elevation of bed to the extent of 9 feet, a 36 foot flood an 
 elevation of bed to the extent of 7 feet, and a 25 foot flood an 
 elevation of bed to the extent of 5 feet 10 inches, the height 
 of flood bears an almost uniform proportion to the height of 
 the elevation of the bed. Where the height of flood is nothing 
 the elevation of bed is also nothing at Damietta. In 1800 
 years, it is thus seen, that for every foot high of the flood at 
 Cairo, the Nile has elevated its bed 2.80 inches, at Thebes 2.34 
 inches, and at the first Cataract has elevated its bed for every 
 foot of flood, 2.70 inches. This furnishes for streams perfectly 
 analagous in all particulars to the Nile, an approximate scale for 
 estimating the rate at which they elevate their beds while un- 
 disturbed by Levees in the distribution of their detrital matter 
 over the adjacent countries. But while such is the rate of bed 
 elevation in unleveed streams, we have seen, as reasoned to 
 above, that the rate of bed elevation must necessarily be much 
 more rapid in rivers confined by Levees. But one special fact 
 confirmatory of this general proposition is, however, within 
 our reach. The Rhine, which is Leveed from the sea almost to 
 its source, has since the Christian era elevated its bed at the 
 City of Mayance, 13 feet 4 inches. The Levee influence in 
 this case has been in operation for but 300 years ; and, there- 
 fore, assuming the rate of elevation in the river when it over- 
 flowed its banks the same as that of the average of the Nile, 
 the bed-elevation for the 1500 years of overflow must have 
 
EMBANKING LANDS FROM RIVER-FLOODS. 43 
 
 been 6 feet, and for the 300 years of Levees be so much as 7 
 feet 4 inches, or six-fold as great. The flood-level of the river 
 Po, it is true, is said to be higher than the roofs of the houses 
 in the city of Ferrara ;~but this statement is so loose that it 
 may mean very much or very little. If the houses referred to 
 be but one story high, the flood-level described in the statement 
 may not be higher above the streets than ten or twelve feet. 
 In London to-day, it would not be considered wonderful if we 
 heard that the Thames, during high tides, stood as high as 
 the eaves of some of the small houses in Blackwall, south of the 
 Thames. And in New Orleans it would not be at all surprising 
 to learn, that during the late floods, the water of the Missis- 
 sippi stood higher than the roofs of some of the little squat 
 cottages on the edge of the swamp sloping toward Lake Pon- 
 chertrain. Originally, marine swamps, as London, New Orleans 
 and Ferrara, had been, it is after all not so very remarkable 
 that the levels of those swamps should be found now, as they 
 doubtless have been from time immemorial, considerably 
 depressed below flood-water. Seeing then that the record is so 
 loose in the case of the Po, it may be assumed that while that 
 record points to a great elevation in the river-surface since the 
 construction of its Levees, such an elevation, from the manner 
 in which it is stated, must not of necessity be held as by any 
 means alarming. So much for the reasoning and the facts as 
 to the elevation of river-levels, whether the rivers be or be 
 not confined by Levees. This question of bed-elevation and, 
 therefore, of surface-elevation, has been made a great bugbear 
 in reference to the embankments along the Mississippi ; but 
 when the few facts known in the case are subjected to exami- 
 nation, only such planters as take a very active interest in their 
 great grandchildren will, while reclaiming the magnificent 
 wastes of the Mississippi, trouble themselves by the reflection 
 that after the reclamation of those lands, they may revert in 
 some future century back to swamp, on the ground that the 
 
44 PRINCIPLES AND PRACTICE OF 
 
 works of reclamation tend to elevate the flood-level of the 
 river, according to the experience of a city 300 miles up the 
 Rhine, at the rate per year of less than one-third of an inch ! 
 
 Incidental to the question of Levees, a few remarks may be 
 added on the subject of Debouch-bars. In a Delta these bars 
 mark the shallowest water of its respective passes ; the volume 
 deepening up-stream until, at the junction of the passes, it 
 reaches its general depth. The Rhone, at Aries 20 miles 
 from the sea has a depth of 43 feet, whereas the depth of 
 water on its bar is but 6 feet 6 inches. This river has five 
 passes or mouths. The Po di Yolano one of the passes of the 
 River Po has a depth on the bar of but 2 feet 6 inches while 
 some seven miles up-stream, that depth increases to ten feet. 
 The same general fact has been observed at all the seven passes 
 of the Nile, and of the numerous passes of the Ganges. This 
 law of Delta-debouch is illustrated forcibly in the case of the 
 Mississippi. The South-west pass the deepest of the whole, 
 has, according to the United States Coast Surveys of 1851 and 
 '52, a depth of about 13 feet, whereas, according to Sir C. 
 Lyell, the river has a depth at New Orleans of 168 feet. 
 
 In Deltas, rivers always divide into branches. Consequent 
 on this branching the loss of volume in each outlet results 
 by the great increase of friction, &c. in a loss of momentum. 
 This loss of momentum, lowering the aggregate carrying- 
 power of the stream, results in a proportional acceleration of 
 deposit ; and therefore, going on from its starting point the 
 branching under the effects of a constant retardation, reaches 
 its limit on the pass-bar. This, then, is the point of greatest 
 deposit, and therefore of least depth ; whereas, the branching 
 point is the point of least deposit, and therefore, of greatest 
 depth. Thus we find the Rhone, the Po, the Nile, the Ganges, 
 like the Mississippi, all shallow in their passes, and deep above 
 the separation of those passes from the main channel. These 
 facts and reasonings on Delta-bars point directly to the natural 
 
EMBANKING LANDS FROM RIVER-FLOODS. 45 
 
 remedy for lowering the water-line through a Delta and remov- 
 ing its bars. The diffusion of the water-flow being the cause 
 of those evils, their remedy lies clearly in its concentration. 
 The condensing of the whole volume of a stream in one channel 
 will, by increasing its momentum, give a carrying power that 
 will remove and transport far out to sea, the silt that, with an 
 inferior carrying power, sinks into the bed of half a dozen 
 passes. The improvement of river-beds, whether for the 
 purposes of navigation or drainage, ought never to lose sight 
 of the prime importance of concentrating the flow, in order by 
 thus increasing the momentum the " scouring" power of 
 that flow to remove the greatest possible amount of deposit 
 from the bed, and thereby deepen the channel ; to propel that 
 deposit out into the distributing currents of the sea, and 
 thereby retard or stop altogether, the extension of the Delta. 
 This conclusion is confirmed by the experiments of Genn6tte, 
 the observations of Guglielmini, and all the subsequent expe- 
 rience of the most respectable practitioners in Hydraulic 
 Engineering. 
 
 The bars of the Mississippi mouths are subjects of great im- 
 portance to commerce. The report of attempts to remove one 
 or more of those bars by dredging, is incredible. Such an effort 
 were a repetition of the story of removing the soil of the Augean 
 stable. The mechanical power engaged in piling up material 
 across the passes of the Mississippi is that of the Mississippi 
 itself; and it were the rankest of folly to attempt to undo the 
 constant work of that power by the puny efforts of some 100- 
 horse-power dredge. The Mississippi itself is the only power 
 that can be brought to bear in the case to undo permanently 
 the work of the Mississippi. The Clyde, a century ago, did 
 not present a navigation-depth of over three feet as high as the 
 City of Glasgow ; but, though the bars and general bed were 
 hard gravel, such has been the effect of concentrating its waters 
 between regular lines of wharfs and jetties that it, to-day, bears to 
 
46 PRINCIPLES AND PRACTICE OP 
 
 the Quays of Glasgow sea-going vessels of some 20 feet draught. 
 Concentration then of its waters in one channel is the only 
 means for removing permanently the Mississippi bars j and 
 thereby preserving for New Orleans a commerce that otherwise 
 must become every day more embarrassed as the Delta-advance 
 adds uncertainty, difficulty, and danger to its communication 
 with the sea. 
 
 But the commercial ground applies also to the other grounds 
 of this course. The concentration of the waters of the Mis- 
 sissippi will not only assist shipment by removing the pass-bar, 
 but will assist drainage by keeping down the water-line. The 
 greater the momentum at the mouth, the greater the power of 
 the river in displacing sea-water, and the greater the displace- 
 ment of sea-water, the greater the outflow of river-water. 
 Thus then does the concentrating of the stream tend to the 
 depression of the up-stream water-level. But the elevation of 
 the water-level in Delta-rivers has been shown above to go on 
 steadily with the extension of the Delta a mile of extension in 
 that of the Mississippi being taken to represent an elevation in 
 the flood-level at New Orleans, of 1J inches, at Friar's Point of 
 5J inches, and of 6J inches at Cairo. While the increased dis- 
 placement of sea-water, as suggested, leads to a proportional 
 lowering of the flood-level, the full effect of that lowering will 
 be experienced permanently by the removal of that constant 
 -cause of increased elevation Delta extension. Now the in- 
 creased momentum resulting from concentrated flow, in dis- 
 placing an increased amount of sea-water, operates necessarily 
 farther out at sea ; and, in so operating, bears the material of 
 river-flow more thoroughly within the distributing influence of 
 the Ocean-currents. The Amazon with its single outlet rushes 
 into the sea with a momentum that forces its earth-laden water 
 out into the Atlantic Ocean for 300 miles. The sea left thus to 
 dispose of the material brought down by that great river, the 
 Amazon has, as a consequence, no Delta. Concentration of its 
 
EMBANKING LANDS FROM RIVER-FLOODS. 47 
 
 waters will accomplish like results for the Mississippi ; and in- 
 deed the Mississippi is much more favorably circumstanced for 
 the accomplishment of those results, in consideration of the 
 direction and position of4ts outflow in reference to that great 
 distributing agency the Gulf-stream. The availability of the 
 Gulf-stream as a distributor for the Mississippi may be inferred 
 from the words of Sir Charles Lyell : " that drift timber from 
 the Mississippi is carried to the shores of Iceland and Europe, 
 and that the fine sediment at the velocity of the Gulf-stream 
 would reach the point of Florida before sinking, and what was 
 not deposited there would even be carried much farther on." 
 Concentration of the water then will not only improve naviga- 
 tion by removing the bar ; but, by increasing the momentum, 
 will, in the resulting increase of outflow, lower the water-line : 
 and, in the resulting limitation of the Delta-growth, will also 
 remove the resulting constant tendency to the elevation of 
 that water-line. 
 
 Having glanced at the special question of the dredging of 
 the Mississippi bar, it may be excusable for glancing now at 
 another question of the same class Cut-offs. The Levee being 
 the special object of our consideration here, no other deviation 
 from it shall be made than that which it is now purposed to 
 enter on. 
 
 The circuitous character of the Mississippi and its tributa- 
 ries is sometimes attempted to be remedied for the purposes 
 of drainage, by opening across the narrow part of a bend- 
 peninsula a direct channel. -This direct channel is known, 
 locally, as a " Cut-off." Now, the current being regulated by 
 the rate of fall, and the rate of fall between any two points 
 being regulated by the distance between those points, the 
 shorter that distance the higher will be the rate of fall, and the 
 more rapid will be the current. If the fall be four feet from 
 the beginning to the end of a twelve-mile-bend, then is the rate 
 of fall in that bend four inches in the mile ; but, if that begin- 
 
48 PRINCIPLES AND PRACTICE OF 
 
 ning and that end be connected by a direct channel of four, 
 miles across the bend, then is the rate of fall increased to 12 
 inches per mile. The velocity, all things else being equal, 
 increases directly as the fall ; and hence does this increase of 
 the rate of fall from 4 to 12 inches increase the velocity, all 
 things else being equal, three-fold. But the -momentum of the 
 stream, all things else being equal, increases as the square of 
 the velocity ; and consequently, when the fall and velocity are 
 increased 1 J times, the momentum is increased 2J times ; when 
 it is increased two-fold, the momentum is increased four-fold ; 
 and when, as in the case of the Cut-off supposed above, the 
 fall and velocity are increased three-fold, the momentum is 
 increased nine-fold. Immense accessions of mechanical effect 
 are thus seen to be evolved by Cut-offs. Now, in ascending 
 the Mississippi, a steamboat encountering a current of five 
 miles an hour, expends in the encounter a mechanical effect of 
 suppose 25 ; then will that same steamboat, in encountering a 
 current of six miles, expend a mechanical effect of 36 ; in 
 encountering a current of seven miles, expend a mechanical 
 effect of 49 ; in encountering a current of eight miles, a 
 mechanical effect of 64. Navigation-resistances running up 
 thus rapidly for every increase of current or shortening of 
 channel the point is soon reached by such shortening, where 
 steam-power becomes totally absorbed. Thus then, do Cut-offs 
 endanger the continuance of navigation. This abstract reason- 
 ing, very true, is disturbed by the practical facts. If the soil 
 cut through were indeed strong enough to withstand the accel- 
 erated current, that acceleration would continue to act through 
 a proportionally contracted cut ; but after a while, the effect 
 of this acceleration, in the constant tendency of the flow to 
 adapt itself to the material of the banks, tells in the gradual 
 widening of the new channel to something like the general section 
 of the river. With ordinary sections thus obtained for itself, 
 the full effect of shortenings on the increased rate of flow, con- 
 
EMBANKING LANDS FROM EIYER-FLOODS. 49 
 
 sequent on increased rate of fall, can apply under, only the 
 supposition of free-outflow at the lower end of the Cut-off, and 
 accelerated supply at the upper end. The engorgement of 
 the channel below and the exhaustion of the channel above, 
 tend, it is true, to divide the effect of the Cut-off between an 
 increase in the velocity within it, and a lowering of the water- 
 line from its lower end to a point considerably up-stream. 
 This modification of the fact of increased velocity, however, 
 must not be held to obviate it altogether. Cut-offs, notwith- 
 standing the corrective influence of channel widening, of 
 engorgement below and of exhaustion above, tend by their 
 rapid rate of acceleration in river-resistances to embarras, 
 and under circumstances perfectly supposable, even to exclude 
 navigation. Every impediment to navigation involves an addi- 
 tion to the cost of shipment ; and hence do the planters who 
 seek relief from a Cut-off, entail (until at least the river shall 
 have restored its disturbed bank-current equilibrium) on all 
 shippers up-stream a greater or a less increase of shipment-tax 
 on their up-stream freights. A Cut-off, then, may thus not 
 only put a whole country under contribution, but may actually 
 deprive it altogether of the benefits of water-carriage. 
 
 But navigation is not. the only interest involved in protesting 
 against Cut-offs. Increased velocity introduced at any part of 
 the river-channel, while the velocity below that part remains 
 undisturbed perse, the result will be that the waters, deposited 
 at the termination of the increased velocity more rapidly than 
 they can be passed off by the receiving velocity, will, as com- 
 pared with their reduced level within the Cut-off, be "ponded" up. 
 True, the additional momentum received by the volume of less 
 velocity, will increase that velocity until at some distance down 
 stream the effect of that additional momentum shall have been 
 exhausted. This fact does not destroy the fact of " ponding" 
 up, but by reducing the " ponding" at the point of termination 
 of the specially accelerated velocity pushes farther down stream 
 
50 PRINCIPLES AND PRACTICE OP 
 
 to the point of exhaustion of the additional momentum of the 
 special acceleration the point of greatest " ponding." The up- 
 stream result may now be glanced at. Passing off the water at a 
 velocity more rapid than that at which it is received, the Cut- 
 off after a while reduces the level of the water in the old-chan- 
 nel ; and this reduction of level, accompanied under the " suc- 
 tion" of the Cut-off with an accelerated velocity, extends up- 
 stream to a point at which the Cut-off " suction" ceases to act. 
 The Cut-off then alters the water-level to a sort of concave 
 curve, beginning up-stream and ending down-stream, the deep- 
 est depression being within the Cut-off itself. This curve 
 extends along the whole length of increased velocity of the 
 flow that increase ending up-stream at the point where the 
 "suction" of the depressed-level of the Cut-off ceases, and 
 ending down-stream at the point where the accelerated momen- 
 tum of the increased fall or velocity terminates. The Cut-off 
 then, is undoubtedly servicable in lowering the water-line 
 between those extreme points, the lowering in the Cut-off itself 
 being greatest ; nor is it open to the drawback charged upon 
 it popularly of overflowing the country down-stream. The 
 increased velocity of the Cut-off, being accompanied with a re- 
 duction of level, discharges no greater quantity of water in 
 the same space of time than that discharged by the original 
 velocity, and original volume. How, indeed, can the Cut-off be 
 supposed to discharge more water than it receives, or to 
 discharge water more rapidly than that water is received ? It 
 discharges only the quantity it receives ; and receives only the 
 quantity that time for time had been received and discharged 
 by the original volume. The popular objection to an occa- 
 sional Cut-off of flooding down-stream is seen thus to be 
 unfounded. And here it may be observed that in considering 
 the effects of Cut-offs on navigation as well as on discharge, the 
 remarks made in each case have been confined to occasional 
 Cut-offs. A system of Cut-offs carried up-stream to the supply 
 
EMBANKING LANDS FROM RIVER-FLOODS. 51 
 
 points of the rain-basin would, however, until the river 
 should have re-established its original regime, or until the 
 surcharged channel should have worked out those modifica- 
 tions of depth, by which rivers usually dispose of accumulated 
 waters present the question of discharge in another light : 
 for the shortenings of 150 miles in the lower reaches of Red 
 River point to a continuance of those shortenings to an extent 
 that will cause the delivery of the flood-waters of that River in 
 three or four-fold volume into the Mississippi. This occurring 
 at periods of like delivery in the other tributaries of the 
 Father of Waters all discharging under the acceleration of 
 Cut-offs the result would, until at least the river should have 
 adjusted its depth to its accumulated floods, threaten along the 
 whole Delta of the Mississippi terrible inundations. 
 
 Grave objection rests also against Cut-ofFs in the extent and 
 degree of their increase in the velocity of river-flow. There 
 is as suggested already a sort of balance between the cohesive 
 strength of a river bank and the abrasive energy of a river- 
 current. When the current exerts on the bank an energy 
 greater than the cohesive resistance of the bank, the result is 
 expressed in caving, shoals, bars, and alterations of channel. 
 The tendency of a river is to go on making changes in its 
 course until the equilibrium between the strength of the bank 
 and of the current are fixed ; and this equilibrium is one of 
 the prime objects of the river in endeavoring to establish its 
 regime. In rocky channels, streams dash over cataracts ; in 
 beds of boulders and compact gravel they rush along in almost 
 foaming rapids ; whereas within alluvial banks they invariably 
 sink down into a gliding flow. In the latter case the total fall 
 may show a high rate of descent ; but the result of dispropor- 
 tionate velocity over the soft soil has settled down, after run- 
 ning through since the dawn of creation the programme of 
 bars, and shoals, and caves, and lakes, and new channels, and 
 old channels, into the sinuosities of to-day. Nature in all this 
 
52 PRINCIPLES AND PRACTICE OF 
 
 is working by rule a rule that, however it may be modified, 
 can in no case be safely broken. The Cut-off then is a direct 
 interference with the constantly operating law that rivers are 
 in eternal progress towards their regime. By disturbing the 
 balance of flow-strength and bank-strength, as struggled to by 
 centuries of natural operation, the Cut-off simply succeeds in 
 throwing back the progress of final result on the part of the^ 
 river into the early stages of the world. Nature at once sets 
 about defining its laws in such cases ; and hence do Cut-offs, 
 in accelerating the energy of river-forces, endanger from end 
 to end of their resulting increase of velocity, violent changes 
 of bank and bed. No Cut-off then can for any time continue 
 to be the bed of the Mississippi River while the soil of 
 the Cut-off is mere soft alluvium. Cavings of the most 
 formidable character must be the consequence ; and extending 
 from end to end of the increased velocity consequent on the 
 Cut-off receiving, however, their greatest development in 
 the Cut-off itself it is quite impossible to tell where they 
 may begin or in what form of evil they may terminate. 
 On Red River they may result in the restoration of its 
 ancient outlet to the Gulf; and thus flooding the whole of 
 Western Louisiana, turn with the characteristic suddenness of 
 a torrent into the Atchafalya. On the Lower Mississippi the 
 Cut-off may reduce to a permanent swamp, either the valley of 
 the Yazoo, of the Lower White River, of the Lower Arkansas, 
 of the Lower Red, or by causing the diversion of the 
 Channel into Manchac, may, in twenty-four hours of its 
 flood-season, reduce the whole of Eastern Louisiana from 
 a teeming plantation to a miserable Lagoon. The Cut- 
 off then, while undoubtedly calculated to lower the adjoin- 
 ing flood-level for the moment, is highly dangerous to 
 navigation, and still more highly dangerous, whether as an 
 agent of accelerated aggregation of water, or of accelerated 
 velocity of flow to all the great interests of life and property 
 on the rich alluvium of the Mississippi Delta. 
 
EMBANKING LANDS FROM RIVER-FLOODS. 53 
 
 CHAPTER III. 
 
 THE LEVEE. 
 
 WATER standing in a vessel or enclosure of any kind, presses 
 with equal force on the bottom and the sides. At ten feet 
 deep the pressure of a column of water of a foot square is the 
 weight of that column 10 cubic feet at 62J Ibs. per cubic 
 foot 625 Ibs. The bottom of the vessel containing this water 
 of ten feet deep, bears a load, therefore, of 625 Ibs. to the 
 square foot ; and the sides of the vessel at the junction with 
 the bottom, bear the same strain. The pressure of standing 
 water, it will be seen from this explanation, increases as its 
 depth ; being for 20 feet deep, 1250 Ibs. to the square foot ; 
 for 40 feet deep, 2500 Ibs. to the square foot ; and this press- 
 ure is for the same depth, precisely the same, square foot for 
 square foot, at the sides as at the bottom. The width of water 
 it will be seen from this proposition has no influence whatever 
 on its m?e-pressure j the width of the Atlantic Ocean, exerting 
 only the same hydrostatic pressure on the shores as a mere 
 thread or film of water of the same depth. The popular opin- 
 ion that the width of the Mississippi affects a proportional 
 pressure on the Levee, it may be remarked here is an error. 
 The side pressure, or in other words, the weight of the water- 
 column at the several points of its depth, goes on increasing 
 from the surface, where it is nothing, to the end of the first 
 foot of depth, where it is 62J Ibs. to the square foot of side ; 
 to the end of the second foot, where it is 125 Ibs. to the square 
 
54 PRINCIPLES AND PRACTICE OF 
 
 foot of side ; and so on, the side pressure at any depth being 
 for every square foot of side, the product of 62 J Ibs. multiplied 
 by the number of feet in depth of the point at which it is requir- 
 ed to find that side-pressure. Supposing them to be exempt 
 from the blows of.waves, and of currents, the pressure exerted 
 on Levees would then be in the proportion, &t every foot from 
 its top, of 1, 2, 3, 4, 5 a regular arithmetic progression from 
 at the top, to the base the section representing pressure 
 being thus at the base, the same number of feet in width as the 
 water is in depth. This gradation of pressure in standing 
 water at its several depths, presents the following geometri- 
 cal form : 
 
 The pressure of the Mississippi then, on its banks rejecting 
 that from the blows of waves, or of currents varies at the 
 several depths as the widths vary in the above figure ; and 
 hence will that pressure be resisted effectively by any earthy 
 matter, impervious to water, embanked in the above form. 
 Any earthy matter, provided it be impervious to water, piled 
 up in the above form, will discharge the quiescent pressure 01 
 the water, because oil earthy matter is heavier than water j 
 
EMBANKING LANDS FROM KIVER-FLOODS. 55 
 
 and consequently the above section if made of water, will not 
 exert a pressure able to overcome the dead weight of the 
 above section, if made of earth or other material heavier than 
 water. But this reasoning rejects all other pressures of the 
 river than its pressure as standing water. -Great forces, how- 
 ever, at, especially, the first few feet in depth are exerted on 
 Levees, over and above the standing pressure, by the incidents 
 of waves and currents. A direct cross-wind, in a reach of a 
 mile wide, discharges the dead-weight of the water upon 
 the bank with the velocity of a wave ; and, therefore, occasions 
 a great accession to the standing pressure of the water for the 
 depth of that wave. The steamboat of the Mississippi, as 
 another producer of wave-motion, is also an agent converting 
 the standing pressure into a^multiple of that pressure by veloc- 
 ity | but the steamboat-wave, acting on the Levee obliquely, 
 produces an increase of pressure proportionately less than that 
 produced by the wave striking it under the impulsion of a 
 wind blowing against the Levee directly. No practical mea- 
 sure of this particular cause of increased pressure on Levees 
 is obtainable ; and, therefore, is this cause disposed of here 
 without any attempt to estimate its measure, in the form of a 
 specific quantity. The wave-blow, whether resulting from 
 wind or boat, is a contingency of Leveeing that must be met, 
 as involving an unavoidable necessity of increase on the size of 
 Levees, over and above that necessary to balance the pressure 
 of standing water. The other head of increased pressure, over 
 and above the standing pressure on Levees, is that of current- 
 blows. Previously to this the force of currents has been 
 referred to in general terms ; but in order to express the 
 importance of that force in the present case more fully, it may 
 be well to present it here, in the form of a specific quantity. 
 Mechanical effect is measured in the compound quantity of the 
 weight moved, and the distance through which it is moved. 
 " Feet-pounds" is the denominational term employed to ex- 
 
56 PRINCIPLES AND PRACTICE OF 
 
 press this effect. 100 Feet-pounds represents the mechani- 
 cal effect expended in removing 100 Ibs. one foot, or 10 Ibs. 
 ten feet, or 1 pound, one hundred feet the mechanical effect 
 expended being in each of these cases, the same in quantity. 
 A current striking directly at, say 6 miles an hour, strikes with 
 a velocity of 8J feet a second. This 8J feet multiplied by 
 itself, (or squared) gives a product of 72J, and this 72j divided 
 by the constant quantity 64*4, shows a quotient of 1|. The 
 quotient so obtained is an abstract quantity, representing the 
 multiple necessary to apply to the dead weight of the striking 
 body in Ibs., in order to bring it for a velocity of six miles an 
 hour, to its mechanical equivalent in feet Ibs. Suppose, now, 
 that a current acts at a velocity of 6 miles an hour for a section 
 of 20 feet deep, then the gross average pressure of this section 
 on the bank, as for standing water, being 625 Ibs. per foot, in 
 length, the mechanical effect expended against the Levee will 
 be, for every foot in length, 625 multiplied by 1|, or 700 feet 
 Ibs. The mechanical effect that will move 700 Ibs. one foot, 
 will move 8,400 Ibs. one inch-; and there being little or no 
 elasticity in a solid bank of earth, the current-blow that forces 
 it back a couple of inches repeated as that current-blow must 
 be assumed to be may be held sufficient to force it back 
 altogether ; and therefore, finally, to sweep it away. Such then 
 is the practical value in Leveeing of the force of currents. 
 The wave-blow, as has been remarked, is an unavoidable con- 
 tingency of Leveeing, but then it must be recollected that 
 while some observers go to the extent of alleging that waves 
 do not involve any increase whatever of pressure latterly, be 
 that pressure what it may, it is at all events confined to the 
 height of the wave a height that in the extreme case on the 
 Mississippi does probably not exceed 18 inches. The wave-blow, 
 then, involves no very formidable accession to the strength 
 of the Levees. Current-shocks, however, are of a very different 
 character ; but on the other hand, unlike the wave-blow, are 
 
EMBANKING LANDS FROM RIVER-FLOODS. 57 
 
 altogether, or to a great extent, avoidable. The force of a 
 wave and the shock of a current represent the aggregate 
 pressure that maybe brought to bear under the most unfavor- 
 able circumstances, in Swelling the dimensions of the Levee 
 beyond the form required under the above reasoning, for the 
 pressure of quiescent water. 
 
 The time will come when flood-waters will be excluded from 
 the magnificent low-lands of the Mississippi, at the cost of haul- 
 ing, from wherever it can be obtained most conveniently, the 
 best material for embankments. The material at hand will 
 continue to be used for some time ; and therefore does it 
 become a matter of necessity to use it with a knowledge of its 
 advantages and its disadvantages. Sand, loam, and clay are the 
 materials at present employed for the construction of Levees, 
 the loam and clay, unfortunately, in small quantities. The 
 weight of water, it will be recollected, is 62J Ibs. to the cubic 
 foot ; whereas that of light sand is 95 Ibs. to the cubic foot ; 
 of loam 124 Ibs. to the cubic foot ; and of stiff clay 135 Ibs. 
 With such a difference as that between 95 and 135 in the mate- 
 rials found at different points, it becomes a matter of importance 
 in designing the cross-section of large Levees, to consider the 
 specific gravity of the material to be used. A varying cross- 
 section of Levee is consequently a necessity of a varying soil. 
 The Commissioner, it may be observed here, was censured at 
 the time by some parties for having given the Levee across the 
 Yazoo Pass and Levees of that locality, a larger cross*-section 
 than that previously adopted as a rule of general application ; 
 but that gentleman would have made a grave mistake, for which 
 his own judgment and perhaps the popular judgment would 
 have censured him to-day, if in determining the dimensions of 
 those Levees, he had not gone to the full extent demanded by 
 safety on the score of weight, in exceeding a standard that, if 
 well adapted to the average material of Levees, was certainly 
 ill adapted to the only material obtainable in the cases in ques- 
 
58 PRINCIPLES AND PRACTICE OF 
 
 tion principally light sand. But besides objections based 
 on the gravity of the materials, others also apply, classifying 
 them into different degrees of adaptation for Levees. "Wash and 
 percolation are two most powerful agents of destruction in the 
 case of river-embankments ; and hence, does it become of the 
 gravest importance, where the choice can - be made, to select 
 such materials as are most cohesive and impervious. The light- 
 ness of a sand bank is but a small disqualification for Leveeing 
 compared with its liability to wash and leak. Its " wash" is 
 not even confined to wave, current and rain j but is carried on 
 actively also by the wind. Sand is liable not only to run and 
 blow away in a dry state ; but in also a wet state is liable to 
 run, or " melt" like so much sugar. But while its lightness 
 lays it open as a material for Levees to great objection on the 
 ground of duration, the worst of its properties in such works, 
 is its liability to percolation. A bank of ample section to 
 resist the total pressure brought to bear on it, when that press- 
 ure acts from the outside slope against the whole weight of 
 the bank, will yield when that pressure becomes transferred 
 from the outside of the bank to some point or plane within it. 
 In the latter case a portion only of the whole mass is engaged 
 in the resistance of the whole pressure. Now percolation of 
 the water into the body of the work, places the Levee under 
 these very circumstances. A thread or plane of water, finding 
 its way into the interior of an embankment, exerts just as 
 much pressure against the earth on each side of it as if that 
 thread or plane were an ocean of the same depth as that thread 
 or plane. As this thread separates the parts of the Levee, 
 the outside water fills up the split or open ; and thus preserv- 
 ing the sand height of water within the split, as at the begin- 
 ning of rupture, the Levee becomes completely rent asunder ; 
 and thus reduced in its aggregate power of resistance, is finally 
 swept away. Porous materials then in water-banks, no matter 
 what be their weight in the banks, tend by the insinuation of 
 
EMBANKING LANDS FROM RIVER-FLOODS. 59 
 
 water threads between their parts, to destruction of those 
 banks this tendency, however, being greatest at the time of 
 the construction of the works, and least at the time when their 
 adhesion shall have been, perfected by the coating by deposit 
 over their external faces, and the insinuation by filtration in 
 their internal pores, of earthy matter. Loam is much better 
 for water banks than sand. Thirty per cent, heavier, it meets 
 all the conditions involved in Leveeing on the ground of 
 weight so much better than sand. Much stauncher in its 
 parts, it is superior to sand in all those serious objections 
 applying to sand for the purposes of water-tight embankments. 
 The very best of those soils obtainable under the present prac- 
 tice on the Mississippi for the purpose of river-banks, is blue 
 clay. Several kinds of this clay are found on the lines of the 
 Levee-works ; but they are all subject to the disadvantage of 
 a greater or a less admixture of fine sand. Perfectly imper- 
 vious to water as they all are, the presence of sand lowers their 
 usefulness partly by involving a lighter weight, but mainly, 
 and sometimes even to a very serious extent, by giving them a 
 tendency, especially after frosts, to melt or run like marl in 
 water. But notwithstanding these draw backs, the clays of the 
 Mississippi bottom furnish its very best material for Leveeing. 
 The different bulks necessary with different soils for the 
 same Levee, has already been pointed out as an item of consid- 
 eration in the use of the materials entering at present into Mis- 
 sissippi embankments. The remarks under this head were, 
 however, confined to the influence on the subject of the different 
 specific gravity of those materials. Another consideration in the 
 premises rests on the fact of differences between their " angles 
 of friction," or in the differences between their natural standing 
 angles or slopes. Experiments recorded in Engineering 
 authors of high personal and professional standing, set the 
 angle of repose, or standing angle, of sand at an angle of 30 
 degrees with the horizon ; of firm loam of from 36 to 45 degrees 
 
60 PRINCIPLES AND PEACTICE OP 
 
 with the horizon j of clays at 55 degrees with the horizon. 
 Using a form more acceptable to the popular understanding, it 
 may be explained that those experiments show the standing 
 slopes of those materials to be as follows : 
 
 For Loam 1 foot high to from Ij to 1 base. 
 
 For Sand .... l foot high to If foot base. 
 
 For Clay 1 foot to | foot base. 
 
 Experiments of this sort cannot be disregarded ; and therefore, 
 though these figures do seem to savor rather more of the closet 
 than of the field in the rapidity of those angles of repose, they 
 are not to be discarded in any reasonings to the practical exe- 
 cution of earthworks. Coupling then the different specific 
 gravities of sand, loam, and clay, with their different angles of 
 repose, an assimilation of the merits of the three waving the 
 question of wash and percolation may be made in terms of 
 the limits of haul, at which it ceases to be economic to reject 
 sand on the spot for loam and clay in the distance. In order 
 to reduce the loosening and lifting of the earths to a common 
 standard, let it be assumed that what might be saved under that 
 head in sand as compared with the other two, and with loam as 
 compared with clay, are balanced by the superiority of clay 
 over both the others, and of loam over sand, in weight, strength, 
 and imperviousness. In consideration of the vegetable matter 
 permeating loam, the porosity permeating sand, and the light- 
 ness and friableness of both, the advantage possessed in these 
 respects by clay are hardly overstrained by being set down for 
 the present purpose, as fully equal to the advantages possessed by 
 sand and loam over clay, as a material for " borrowing-pits." The 
 retentive properties of clay, and in a less degree of loam, may 
 be said to increase the difficulty of excavations in that material 
 in a flat country ; but the clay of the Mississippi flats, resting 
 'invariably in thin layers on sand, the shallow and wide-cuts 
 necessary therefore, for clay-pits, may be made perfectly dry- 
 by running up through them at starting, a narrow tap-drain to 
 
EMBANKING LANDS FROM RIVER-FLOODS. 61 
 
 the depth of the sand. Assuming then the three materials 
 equally costly for loosening and lifting, this equation of theL 
 merits may be examined as a question of haul. The following 
 figure shows in the brokea line, a cross-section of Levee having a 
 crown of 3 feet wide and a base of 21 feet the side-slopes cor- 
 responding to the angle of repose for sand, that is to say, cor- 
 responding to the least angle at 
 which sand will stand. The white 
 line in the figure shows a Levee of 
 clay, the crown being 2 feet and 
 the base 15 feet every part of this 
 latter being deduced from the form- 
 er in proportion of the weight of 
 sand to that of clay 95 to 135 and 
 therefore presenting, at all points, 
 a resistance to the horizontal thrust 
 of the water equal to that presen- 
 ted at corresponding points in the 
 larger section (the broken line) of 
 the Levee of sand. Two feet wide 
 at crown, for example, presents as 
 great a resistance in the case of 
 clay, as 3 feet wide does in the case 
 of sand ; 15 feet wide at base pre- 
 senting as great a resistance with 
 the use of clay, as 21 feet wide at 
 base does with the use of sand. 
 This figure, then, illustrates the 
 effect of difference in the weight 
 of the two materials in regulating 
 the size of Levees. But this differ- 
 ence is still further increased un- 
 der considerations arising out of 
 their varying angles of repose. The increase of pressure has 
 
62 PRINCIPLES AND PRACTICE OF 
 
 been already shown to go on from the top, under extreme con- 
 ditions at an arithmetical progression ; and this arithmetical 
 progression of Levee-pressures or strengths has also been shown 
 to express itself practically in an aggregate side-slope of 45 
 degrees a total slope of one foot base for each foot in height. 
 The preservation of equal strength at all parts of the Levee does 
 not require, therefore, a greater width under even the most 
 unfavorable circumstances than (whatever may be the pro- 
 per width of crown,) side slopes from each side of crown 
 at a rate of one-half foot horizontal to one foot vertical. 
 Such a section may be said to be, in general, the section of 
 uniform strength. The strength of any thing being, according 
 to the mechanical axiom, the strength of its weakest part, an 
 excess of strength at any one part is, it is almost needless to 
 observe, a waste of material in Leveeing, and consequently a 
 waste of money. In practice, however, it is impossible to con- 
 form to the section of uniform strength in Levees ; seeing that the 
 controlling consideration rests in the standing angle of material. 
 The standing angle of clay has been set down at eight inches 
 base, to one foot in height ; and, therefore, may be held to 
 conform closely 'to the section of perfect economy of material 
 the section of uniform strength. 21 inches of base for every 12 
 inches of height, being the standing slope of sand, that material 
 is seen in the excess of its natural section over the section of 
 equality of strength, to involve in Leveeing a very large waste 
 of material ; and, therefore, of money. In a Levee having a 
 3 feet crown, a 21 feet base, and a height of 5.20, as shown by 
 the broken line in figure 2, the area of cross-section is 62.40 
 square feet. This Levee, it must be recollected, is one of 
 unequal strength ; and, therefore, measuring its effective 
 strength by its weakest part its 3 feet crown we find the limit 
 of its actual resistance to be, when made of sand, as (3 feet x 
 95 Ibs.) 285. A clay Levee of 2.11 feet crown sloped down, 
 at the standing angle of clay, to a base of 9 feet for 5.20 feet 
 
EMBANKING LANDS FEOM RIVER-FLOODS. 63 
 
 high contains within it the slope of uniform strength ; and 
 consequently, its crown being its weakest part, the limit of its 
 effective resistance is as (2.11 X 135) 284.9. This clay Levee 
 of 2 feet crown, and 9 feet base presents, then, precisely the 
 same resistance to water-pressure as does the same Levee of 
 the game height, having a crown of 3 feet, and a base of 21 
 feet. The cross-section of the clay-bank in this case, is 29 
 square feet ; while, as has been said above, that of the sand is 
 62 square feet. But practice goes still further in increasing 
 this disproportion between the different quantities necessary 
 in Levees of sand, and in corresponding Levees of clay. The 
 standing angle as presented in theory, must be deviated from 
 in both sand and clay to meet, in practice, the contingencies 
 of floods and rains. Lighter, looser, and less adhesive than 
 clay, the flattening of slopes in sand below that of the angle, 
 or slope of repose, must be much more considerable in practice 
 than that in the heavy concreted and adhesive bank of clay, to 
 resist, without endangering the effective strength or stability 
 of the bank, the active washes of rains and waves. The prac- 
 tice, however, in these cases is so loose and various, that it 
 cannot be expressed safely by a rule. Disregarding it 
 altogether, however, and confining the equation of the two 
 materials to the simple fact of the difference between their 
 strict standing angles, 26 yards of clay are seen to be equal in 
 a Levee of 5 feet high, to 58 yards of sand in accomplishing 
 the object of all Levees effective resistance to floods. In a 
 Levee of 10 feet high, 43 yards of clay are as effective as 102 
 yards of sand ; and in a Levee of 15 feet high, 60 yards of clay 
 accomplish all the purposes of 146 yards of sand. At 15 cents 
 per cubic yard, the difference in money between the employ- 
 ment in a 10 feet Levee of 43 yards of clay, and the corres- 
 ponding quantity of sand, is $8.85 in favor of the employment 
 of clay. Supposing, under this view of the case, the sand to 
 be found on the site of the Levee, while the clay cannot be 
 
64 PRINCIPLES AND PRACTICE OP 
 
 obtained without haulage from some distance, the great objec- 
 tion to the employment of sand for this purpose, suggests the 
 enquiry : to what distance are the parties interested bound by 
 the foregoing considerations to haul clay to their Levees ? 
 $8.85 are available, it has been shown under the foregoing 
 comparison, for expenditure in obtaining the clay as compared 
 with the cost of the sand on the spot ; and this $8.85 distribu- 
 ted over 43 yards of clay, shows an available amount for the 
 haulage of clay of 20 cents per cubic yard of clay. In numer- 
 ous instances this rate per yard will cover all the inconvenien- 
 ces of haulage to the Levees, for a distance of half a mile. To 
 sum up these remarks : it may be concluded that, supposing 
 sand to be, under any necessity whatever, fit material for the 
 construction of river embankments, taking the cross-section of 
 equally strong Levees of the two materials, comparing those 
 cross-sections according to the data furnished in the standing 
 angles of the materials, and setting down for the moment, the 
 lightness and porosity of sand, as compared with the heaviness 
 and imperviousness of clay as material for water-banks, at the 
 mere difference in cost of excavating the two, all the immense 
 advantages of clay over sand, not covered by the assumption 
 made here in the case, may be secured at the same cost as 
 sand, by hauling clay to the site of a Levee from a distance of 
 half a mile. In practice, this undoubted fact and the impera- 
 tive duty that it points to, may be found one of very frequent 
 and profitable application ; for, in several cases, clay can be 
 found in abundance in the Yazoo Valley, within half a mile of 
 existing Levees of almost unmixed sand. In the bottoms and 
 banks of the creeks of the out-fall behind the Levees, in the 
 beds of the old and dry lakes, so common behind those Levees, 
 in the hundreds of cypress-swamps in the neighborhood of the 
 works, and on the surface of the higher lands, the contractor 
 will find large quantities of strong, pure clay. The make-shift 
 river-embankments of the State of Mississippi, before those 
 
EMBANKING LANDS FROM RIVER-FLOODS. 65 
 
 works took the shape of a system, under the strong and able 
 mind of Col. Alcorn, have already advanced to something like 
 scientific conditions in plan and section ; but must make still 
 further progress in order to fulfill all the conditions of cheap- 
 ness and efficiency. Progress in those works points to a 
 discrimination in the use of the materials ; and, therefore, to 
 considerations beyond those of the mere accident of the soil 
 on which they are to be built. Sand is, in fact, utterly unsafe 
 in a water-bank, and, therefore, unfit for any works designed 
 for the protection of property from overflow. Break after 
 break, in such Levees, is going on with its lesson of instruction 
 to the necessity that first felt obliged to employ sand ; and as 
 the property suffering from such breaks, becomes more and 
 more valuable, the time is approaching when the question of 
 material in the Mississippi Levees will be considered by the 
 owners of property behind them, as a question of insurance. 
 Sand will, by and bye, be either altogether rejected in Levee 
 making, or used only in positions where its properties can be 
 turned to usefulness j* and in order to open the way for this 
 purpose in the right direction, the general question of its 
 merits as compared with clay is here considered for the infor- 
 mation of the planter. The unthinking will, probably, under- 
 value the reasonings employed in the case, as what a certain 
 gentleman in Mississippi would call " College" nonsense ; but 
 men of reflection will recollect that progress knows no road 
 but that pointed out by observation, reflection, and calculation. 
 Discrimination between the materials at hand is the first object 
 aimed at in the foregoing remarks on those materials; the 
 haulage of the best material for a short distance is the next object : 
 and, following that, the haulage of the material to the full extent 
 as between sand and clay of half a mile ; the next step in 
 advance being one that is also yet to come the total rejection of 
 sand, as a building material, from the Levees of the Mississippi. 
 
 * See note, page 80. 
 
 5 
 
66 PRINCIPLES AND PRACTICE OF 
 
 The materials at hand will, however, continue to be used for 
 some time in the Mississippi embankments. It becomes, there- 
 fore, important to consider the best means for reducing the 
 disadvantages of their use to the smallest possible amount. 
 The leaky property of sand is its greatest objection ; but this 
 may be overcome to a large extent by constructing within the 
 bank a vertical wall from crown to base, of clay, thoroughly 
 tramped and puddled. This " puddle wall*' ought to contain 
 no vegetable matter, such as grass or roots of any kind ; and 
 when wet to a proper consistency ought to be shoveled into 
 the place left for it in the sand-bank as the bank goes up, 
 layer after layer. When the puddle is in its place it ought to 
 be tramped down well ; it is indeed beaten down in water- 
 banks in England and Ireland with a heavy maul or rammer. 
 
 The practice of cutting out a trench for the puddle, or 
 " muck ditch" as it is called on the Mississippi, in the natural 
 surface of the ground, is generally useless, and some times posi- 
 tively mischievous. Where retentive subsoils exist under the 
 base of the proposed bank, then it is certainly a clear gain in 
 staunchness to run down the puddle-wall of the Levee to a 
 bond with the underlying impervious earth. But the experi- 
 ence along the shores of the Mississippi leads to the presump- 
 tion that, in those cases where the sand does not commence on 
 the surface, a ditch of three feet deep is more likely to present 
 a bottom of sand than of loam, or clay. The rationale of those 
 " muck ditches," as they are called locally, rests on their use- 
 fulness in preventing leakage ; and, therefore, supposing the 
 ditch and wall carried up regularly with a puddle, those 
 ditches in a great majority of cases failing to reach a more re- 
 tentive soil than that at the surface of the ground, involve in 
 all those cases an utterly resultless waste of money. Besides, 
 to undertake to prevent leakage through the porous earths of 
 the natural shores of the river, is a hopeless labor ; and so 
 far as the strength and durability of the Levees are concerned 
 
EMBANKING LANDS FROM RIVER-FLOODS. 67 
 
 is a labor, also, perfectly useless. It accomplishes nothing 
 whatever, for the artificial embankment. But in some cases 
 these " muck ditches" are, as already stated, mischievous. 
 Across those lagoons or -creeks which are dry during periods of 
 low-water, the foundation for banks consists generally of a hard 
 crust of clay for a few feet thick, overlying quicksands or thin 
 puddles. These crusts, like the grillage of timbers used for 
 the foundations of some Engineering works, are highly valuable 
 in those situations, by diffusing the weight of the superincum- 
 bent Levee over a wide bearing ; and thus, though unequally 
 loaded by the necessary cross-section of the Levee, assist, in 
 proportion to their strength, to distribute that bearing equally. 
 This, where not sufficient to obviate the sinkage altogether, 
 reduces it considerably ; and in bringing a large area to act in 
 the resistance, assists to guarantee with the least possible 
 "sinkage," and, therefore, least possible loss of work of money 
 a finally well-sustained foundation. The " muck ditch," how- 
 ever, cuts this natural platform for the Levee in two parts ; 
 and over this cut, the greatest weight that at the crown 
 pressing vertically, acts as with a leverage in bending down, 
 and finally breaking off the natural crust of the surface. The 
 necessity therefore follows, under those circumstances, of em- 
 ploying an excess of earth in forcing out laterally, and forcing 
 down vertically, the running sand or soft puddle of the underly- 
 ing foundation in order to compress those soft materials into a 
 compactness sufficient to present an effective resistance to the 
 weight of the superincumbent embankment. 
 
 Rejecting then the practice of cutting a muck ditch along the 
 base of the Levee, it is recommended here that the earth of 
 the base be loosened for six or twelve inches in order to secure, 
 between the artificial and the natural bank, a proper bond. 
 Indeed where the natural surface is loam or clay for any con- 
 siderable depth, it would be highly judicious in order to prevent 
 grasses or other vegetable matter of retarding the bond between 
 
68 PRINCIPLES AXD PRACTICE OF 
 
 the Levee and the ground, to skim the surface ; and one good 
 purpose thus served, the sod so skimmed off the base may, on 
 the completion of the Levee, realize the further good purpose 
 of staunching it by laying them in a close coating on its water- 
 slope. Be the substitute, however, for the muck ditch what it 
 may, the present practice in the case, if even not useless and 
 unsafe, is certainly absurd when it is recollected that it is in 
 fact a " muck ditch " with the important exception of the " muck." 
 The lightness of sand is a great objection against the use of 
 that material in water-embankments. Sand is constantly carried 
 away in immense quantities by the current of the Mississippi ; 
 and therefore, to invest money in banks of sand for the exclu- 
 sion of the Mississippi floods, does not seem to be a policy very 
 remarkable for its astuteness. As its porosity presents the 
 use of sand in Levees in the shape of a question of safety, its 
 lightness presents its employment in those works in the shape 
 of a question of maintenance. Rains constantly washing the 
 particles in its crown down to its sides ; and washing those in 
 its sides out upon its base, the weakest part of a Levee the 
 crown is undergoing constant reduction in its dimensions, 
 and consequently in its strength. Current-washes and wave- 
 washes on the water-side co-operate in times of high-water with 
 the rain-wash at other times, in reducing the strength of Levees 
 thrown up in sand. Maintenance becomes thus in the case of 
 sand Levees, a serious outlay. To remedy this and indeed at, 
 the same time assist its want of imperviousness the most con- 
 venient course is, to cover the water-slope of such banks with 
 as thick a layer as may be obtained of clay, if obtainable, -or if 
 not with as thick a layer as may be laid on according to the above 
 suggestion, from the quantity of earth obtainable by collecting 
 the loam of the adjoining surface. In Ireland it is very common 
 to face water-slopes with grass-sods laid on their flat beds 
 with regular headers and stretchers, as in Ashlar work, the 
 whole being cut down to the plane of the slopes. Under 
 
EMBANKING LANDS FROM RIVER-FLOODS. 69 
 
 the direction of Mr. M. B. Hewson, I have myselt conducted 
 large quantities of this work for the Board of Public Works, 
 under the measures for the drainage and navigation of Irish 
 Rivers. In the South ""sods " are not generally obtainable ; 
 but all the advantages resulting from their use in water-banks, 
 may be obtained there by sowing the seeds of some southern 
 grasses in a coat of loam-dressing on the slopes of those banks. 
 Bermuda grass is well adapted for the preservation of artificial 
 banks ; but though often employed for that purpose on Rail- 
 roads in the Northern States, is excluded from use on banks in 
 the South-west by what would seem to be no better than a mere 
 prejudice. The rapidity of its growth is not the only recom- 
 mendation for the employment of Bermuda grass on Levees ; 
 for it possesses the further recommendation of growing in both 
 shade and sun. During high-water it will catch a great quan- 
 tity of sediment ; and by the consequent annual coating of 
 impervious earth, will add to the strength and durability of 
 the Levee. The decay of the tops and blades of this grass will 
 also assist in covering the w r ater-slope of the Levee with an 
 annual coating of impervious matter, and in the case of Levees 
 built of sand, will thus tend greatly to the correction of their 
 two great shortcomings washing and leakage. A hedge ol 
 Osage Orange, set closely along the inside slope, by excluding 
 both travelers and cattle, and a coat of Bermuda grass set on 
 both sides, by obviating wash whether of rain or current, will 
 save the parties interested in Levees, a large annual sum for 
 their maintenance. 
 
 In Europe, generally, it is usual to protect embankments by 
 growing on their top and sides thickly growing grasses. In 
 parts of Holland straw is used for the same purpose. Twisted 
 into ropes about 2 inches in diameter, it is laid on the face of 
 the bank, and pinned down with hooked or forked sticks ; rope 
 after rope being added each in close contact to the previous 
 one is so laid down until the whole slope is covered with a com- 
 
70 PRINCIPALS AND PRACTICE OF 
 
 plete mat of straw. Vegetation in course of time^commences 
 underneath the straw, and blades of grass making their way 
 between the ropes, the whole becomes a compact sheeting. 
 Fascines, hurdles, and brush-wood, are sometimes employed for 
 the same purpose. Large stone slabs are often used by En- 
 gineers in Bombay for the protection of the slopes of heavy 
 embankments from the weather. So important is it found in 
 experience all over the world, when it is worth while to go to 
 expense in the construction of embankments, to go to further 
 expense for their efficiency and preservation. Any thing that 
 is worth being done in waiter-works is worth being done pro- 
 perly and well. 
 
 The standing slopes that have been given above for sand 
 loam and clay are the standing slopes of those materials when 
 dry. The dry slope and the wet slope of all earths are, how- 
 ever, more or less different. The same earth that stands in 
 practice at an angle of 2 to 1 in a dry position, will require in 
 a wet situation a slope of 3 to 1. Some earths have been 
 found to require in a wet situation slopes so low as 4 to 1. A 
 river embankment involves both the two distinct conditions of 
 dry and wet slopes the inside being necessarily regulated by 
 the conditions of dry slopes, the outside being subject to the 
 tests applicable to icet slopes. Wetness and dryness, however, 
 do not cover the whole difference between the circumstances 
 of the dry and the wet slopes of the Levee ; for the outside 
 slope, in addition to the disadvantage of wetness, is also sub- 
 ject to the further disadvantage of waves and currents. The 
 practical facts of the case establish, therefore, the general 
 proposition that the external or wet slope of the Levee ought 
 to be less in rate than that on the inside, or dry slope. If the 
 wet slope be sufficient for the necessities of its position ; then, 
 to carry out the dry slope at the same rate is a simple waste 
 of material, and consequently, a waste of money. In six cases 
 of well known water-banks in England, the inside or dry slopes 
 
EMBANKIXG LANDS FROM RIVER-FLOODS. 71 
 
 vary according to the material, from an incline of 1 to 1 to an 
 incline of 3 to 1, averaging an incline of 1 J to 1, or about 30 
 degrees with the horizon the outside or water-slopes, in those 
 six cases, varying from an incline of 2| to 1, to an incline of 5 
 to 1 the six showing for the water-slopes an average incline 
 of about 3| to 1. or about 16 degrees with the horizon. Natu- 
 ral water-slopes, formed under water, such as those of bars in 
 the Mississippi, or other rivers, vary from an incline with the 
 horizon of from 5 to 30 degrees the average of these two 
 extremes being 17J degrees, or nearly 3 feet of base for every 
 foot in height. 
 
 The height of a Levee above high- water mark has been set 
 down, by practice along the Mississippi, at 1\ feet, and at 3 
 feet. A Levee system, as has been shown in another chapter, 
 does not occasion an immediate elevation of the previously 
 established flood-level. General considerations, then, have 
 nothing to do with this head of the subject, seeing that it is a 
 head proper to local specialities. The width of a river and 
 the force of the winds regulate the height of its wind-waves ; 
 while the width and current of the river, coupled with the 
 speed, load-line, and midship section of its steamboats, regulate 
 the height of its steamboat-waves. Two feet would, probably, 
 plumb the highest wave resulting from the accidental combi- 
 nation of the greatest wind-wave with the greatest steamboat- 
 wave rising on the Levees of the Mississippi. The looseness 
 of the observations made as to high-water in that river, coupled 
 with the further consideration that those observations may not 
 go sufficiently far back, in time, to embrace that particular 
 combination of circumstances which produce the highest pos- 
 sible flood, suggest the propriety of basing the height of the 
 Levees on a margin over and above the strict inch of the 
 recorded high-water mark. Allowing 24 inches for the height 
 of the maximum wave striking the Levee, 12 inches additional 
 is certainly not too large an allowance for the contingencies of 
 
72 PRINCIPLES AND PRACTICE OF 
 
 the case, in determining the height above high-water of the 
 Mississippi Levees. Close enough, already, no reason certainly 
 appears to show why, the standard of an excess of 3 feet above 
 the highest known flood should be lowered ; and it is, there- 
 fore, safer to conclude that experience, as in the case of the 
 State of Mississippi, has settled the question between economy 
 and safety in the matter, by fixing the height of Levees at 
 three feet above -the highest level of quiescent flood water in 
 the river. Four feet of an excess would, of course, be still 
 safer. 
 
 The crown-width of Levees is a question less of rule than 
 expediency. In England, water-banks have an average width 
 at top of 3 feet. In Ireland, the top-widths of embankments 
 for drainage, are about the same. In Holland, however, the 
 Dikes, when employed for road-ways, are exceptionally wide 
 across the crown. The Sea-banks of Holland are, in any event, 
 no guide in fixing on the dimensions of river-embankments ; 
 nor, indeed, are the size of water-banks in England, or Ireland, 
 quite a safe guide for such banks when subject to the wash of 
 the immensely heavier rain-fall of the Lower Mississippi. 
 Local experience, then, is the best, and indeed, the only guide 
 in this matter. In Arkansas, it is true the local experience 
 has been had under circumstances which make it start from 
 too high a point ; with the view of a necessity for adapting the 
 section of the Levee to the width of the river, some absurd 
 and ignorant theory has led to the rule, that all Levees in that 
 State be as many feet in width at crown as they are in height. 
 These works, however, have been carried out, chiefly, without 
 the guidance of professional skill. In the State of Mississippi, 
 the practice has settled down into a width of 5 feet for the 
 crown of Levees generally. My own practice and experience 
 lead me, however, to the conclusion that 3 feet is sufficient to 
 cover all the coritingencies of rain-washings, cattle-tramping, 
 &c., during, and for a sufficient time subsequent to, the harden- 
 
EMBANKING LANDS FROM RIVER-FLOODS. 73 
 
 ing and cementing of the works. Economy, however, in this 
 case, as in that of height and all other dimensions, is the only 
 limit ; for safety is always the gainer by an excess of section. 
 
 Shrinkage had been included in the considerations regulating 
 cross-sections in the Mississippi practice. The generalizing 
 pursued in this case was as erroneous in execution as in 
 that of the " muck ditch. " Different materials shrink in banks 
 differently. Its particles fine and loose sand, however 
 loosely it may be shovelled together, fills its space closely ; 
 and, therefore, whether wet or dry, settles at a very small dimi- 
 nution of its original bulk. In time, too, the process of this 
 settlement is short. One-tenth of its original content is 
 a liberal allowance for shrinkage in sand. Tough clay, however, 
 is banked up under different conditions. Adhesive in its char- 
 acter, it is loosened and lifted in lumps ; and from the size of 
 those lumps, their shape, and their resistance to a change of 
 form, they fall together in an embankment without compactness. 
 Settling of such a bank is the process of filling up all the cavities 
 and spaces existing thus between its parts ; and hence in the 
 case of lumps so large and stiff as those of clay excavations, is 
 the amount of this settling quite considerable generally about 
 one-fifth of its original bulk. The time expended in the settle- 
 ment of clay is longer than that in the settlement of sand. 
 The different modifications of material between sand and cky 
 settle as to time and quantity, in proportion to the respective 
 amounts in their constituent parts of sand and of clay. An 
 average of 16| per cent, then, the allowance generally made in 
 Mississippi, waving the objection to the principle in the case, 
 is not, in all probability, a great error on either side from the 
 strict justice as to the quantity. Two inches to the foot for the 
 height, with proportional increase to the side slopes without 
 any addition to the width at base, is added in practice to the 
 intended settlement section of the Levee, in order to cover the 
 loss of form and size by " shrinkage" or settlement. Accord- 
 
74 PRINCIPLES AND PRACTICE OF 
 
 ing to the variations in the height of the bank from the surface 
 of the ground an addition of one-sixth was thus added on to 
 it, over and above the gradient line of 3 feet above flood. 
 
 The section of a water-bank is a mixed question of theory 
 and practice. In examining its several parts here, it has con- 
 sequently been found unavoidable to mix up the abstractions 
 of the subject with its working facts. Having, however, made 
 those examinations under the several heads of slope, height, 
 and crown, the next point to be made is the combination of the 
 results in the elimination of the practical cross-section. And 
 first for sand. The .width of crown being taken uniformly at 3 
 feet, the slopes of a Levee, showing the strict angles of its stand- 
 ing slope, on the inside for dry sand and on the outside for wet 
 sand, is represented by the light line in fig. 3. The broken 
 line represents the section adopted in the present Levee 
 practice of the State of Mississippi ; the heavy line in that 
 figure representing the section resulting from the employment 
 of the surplus material used under that practice, in increasing 
 the resistance of the material when distributed at the strict 
 standing slopes of the wet and dry sides of the section, in a 
 manner to produce an equal increase of the resistance of the 
 material of those slopes to motion from wind or wash. The 
 section, figure 3, applies to sand. It adopts the quantities of 
 the practice at present pursued in Mississippi ; and redistri- 
 butes those quantities on the basis of the respective angles of 
 repose of the material in dry and in wet slopes. Fig. 4 repre- 
 sents a cross-section of equal strength with that of fig. 3, the 
 one being assumed to be carried out in sand, the other in clay. 
 The strength of the sand-section being assumed for its basis, 
 this clay-section is simply an addition to the wet and the dry 
 slopes of repose of material equal in quantity to the additions 
 made in fig. 3, to those slopes for sand. 
 
 The sections in the two figures given here show again the 
 relative proportions necessary for equal strength in clay and in 
 
EMBANKING LANDS FROM RIVER-FLOODS. 
 
 75 
 
76 PRINCIPLES AND PRACTICE OF 
 
 sand. The reduction, however, of the width of crown from 3 
 to 2 feet in the case of the clay is objectionable in practice. 
 The considerations presented when reviewing the practice pur- 
 sued in this particular in Mississippi suggest the expediency 
 of adopting the width of crown in all cases, of 3 feet ; and there- 
 fore, is the section above given on the supposition on either the 
 inside or the outside slope of a Levee, of an addition of clay 
 having a uniform thickness of 12 inches as represented by the 
 second heavy line. This, then, shows a Levee as compared 
 with that of the section in sand, of considerably increased 
 strength the excess at the point of least resistance the 
 crown being over and above the sand-bank nearly 50 per cent. 
 The standing angle of each material being taken as the basis of 
 the respective sections, the additions made to those standing 
 angles for the purpose of increased stability the addition made 
 in the case of clay giving the same additional width of base as 
 in the case of sand constitute in consideration of the superior 
 weight and adhesiveness of the material, a greater additional 
 stability over and above that of the section of the strict slopes 
 of repose. The resistance to weather and current are greater, 
 therefore, in the case of a clay Levee of the section shown in 
 fig. 3^ than of the section shown in fig. 4, thrown up in sand. 
 The rule adopted in Mississippi for the proportioning of Levees 
 is seen to be wrong in its recognition of equality of their dry 
 and their wet slopes. But this rule is exceedingly inconvenient. 
 Six to one being the proportion regulating the width of base 
 in terms of the height in the State of Mississippi, the base for 
 a Levee of 3 feet is 18 feet, of 6 feet is 36 feet, and of 12 
 feet is 72 feet. The crown in each of these three Levees being 
 5 feet wide, the base of the slopes themselves (deducting the 
 width of crown) is for the 3 feet Levee 13 feet ; for the 6 feet 
 Levee 31 feet ; for the 12 feet Levee 67 feet the rate of slope 
 on each side being thus : for the 3 feet Levee 2 2 4 4 to 1 ; for the 6 
 feet Levee 2S to 1 ; for the 12 feet Levee 2 to 1. Every 
 
EMBANKING LANDS FROM RIVER-FLOODS. 77 
 
 height of Levee is thus seen, under the application of the Mis- 
 sissippi practice in this particular, to present its own peculiar 
 slope ; and consequently does the whole line of Levee in that 
 state present a constant succession of varying slopes a different 
 slope for every different height. The inequality of the stability 
 resulting from these circumstances is a mere theoretical con- 
 sideration too trifling to be regarded seriously in practice. The 
 objectionable feature of the case, however, applies to its practi- 
 cal inconvenience to the Engineer in estimating the quantities 
 of the work. At this moment it does not appear that calcula- 
 tions can be made with mathematical exactness in such a case 
 by any established formula ; but be that as it may, it is very 
 clear that such calculations must of necessity be tedious and 
 complicated. The subject of calculation is, however, treated 
 more fully in its proper place. The slopes ought to be laid 
 down in terms of the height exclusive of the width of crown a 
 quantity that is a constant for all widths of base. To apply the 
 inferences from the sections given in figures 3 and 4 to meet 
 this expediency of equality of rate of slope for all heights, it 
 may be observed that those sections are given for a height of 
 seven feet. They show for that height a wet slope, for sand of 
 3| to 1, for clay of 1 to 1 ; and a dry slope for sand of 2J to 1, 
 for clay of 1} to 1. For a height of 10 feet these slopes would 
 for sand under the Mississippi practice be still flatter. As a 
 rule then of constant application for all heights, these sections 
 may be generalized into the following : in clay the inside slope 
 to be 1J to 1, the outside to be 1| to 1 ; while in sand, the 
 inside slope is 2J to 1, the inside 3J to 1. In consideration, 
 however, of the fineness of the sand available along the Mis- 
 sissippi, and of the greater or less mixture of that sand in all 
 its clays, and also in consideration of the necessity of simpli- 
 fying calculations to the level of the expertness superintending 
 the works, it is recommended here that the rule for constructing 
 Levees on the Mississippi be (as the conclusion of the foregoing 
 remarks on base, crown and material) as follows : 
 
78 PRINCIPLES AND PRACTICE OP 
 
 In Sand. 
 
 Inside or dry slope 2i 1o 1. > oft. 
 
 Outside or wet slope 84 to 1. \ crown 3 fect 
 
 In Clay. 
 
 Inside or drv slope l to 1. ) f . 
 
 Outside or vet slope 2 to 1. } crown 3 lect 
 
 The clay-section supposes the rejection from the bank of all 
 sand. For any admixtures of the two, no matter how small the 
 proportion of that material in the admixture, it would not be 
 safe to deviate from the proportions recommended above for 
 sand. In order to show the ease with which this new practice 
 may be substituted for the present faulty one, the following 
 form of calculation is presented here : 
 
 Station. Height of Leveo. Inside slope. Outside slope. Crown width. Total width of base. 
 
 41.40 
 46.20 
 43.80 
 58.80 
 73.20 
 81.00 
 67.80 
 45.60 
 
 To guard against mistakes in making this calculation, it is 
 recommended that after copying from the field notes the heights 
 corresponding to each station, each of the other columns be 
 carried out separately. Otherwise the multiple of 2J in the one 
 case will be often used by mistake for the other multiple and 
 vice versa. 
 
 
 
 2J to 1. 
 
 3J to 1. 
 
 
 I 
 
 6.40 
 
 16.00 
 
 22.40 
 
 3.00 
 
 2 
 
 7.20 
 
 18.00 
 
 25.20 
 
 3.00 
 
 3 
 
 6.80. 
 
 17.00 
 
 23.80 
 
 3.00 
 
 4 
 
 9.30 
 
 23.25 
 
 32.55 
 
 3.00 
 
 5 
 
 11.70 
 
 29.25 
 
 40.95 
 
 3.00 
 
 6 
 
 13.00 
 
 32.50 
 
 45.50 
 
 3.00 
 
 7 
 
 10.80 
 
 27.00 
 
 37.80 
 
 3.00 
 
 8 
 
 7.10 
 
 17.75 
 
 24.85 
 
 3.00 
 
EMBANKING LANDS FROM RIVER-FLOODS. 79 
 
 CHAPTER IY. 
 
 DETAILS OF LEVEE-WORKS. 
 
 EXPERIENCE is made up in Leveeing, as in all other works, of 
 a knowledge of its details. Success in Leveeing, as in all other 
 matter of practice, is regulated by paying due regard to small 
 particulars. The intention of this contribution to the sys- 
 tematizing of those works excludes from this book a full 
 examination of all the specialities that have arisen in the course 
 of my experience on Levees in both Mississippi and Arkansas. 
 Particulars, such as occur often or involve important consider- 
 ations, are perhaps not excluded by the general plan laid down 
 for my guidance in these pages. Attention may, therefore, be 
 directed to a few considerations suggesting themselves by the 
 special experience of my Levee-works. In preparing the 
 ground for Levee-base it is necessary to clear and grub the 
 whole thoroughly, leaving neither stump, root, brush, weed, nor 
 even grass. This important duty is generally done with great 
 carelessness. Before the work of embankment is commenced, 
 all the timber, roots, weeds, and grass removed from the foun- 
 dation ought to be disposed of in piles and burned to ashes. 
 This rule should be enforced rigidly. It is the only means of 
 guaranteeing the exclusion of all unfit material from the body 
 of the Levee. In Arkansas particularly, and in Mississippi to 
 a very large extent, to place logs, brush, and even whole trees, 
 in the body of a Levee was an impropriety of not exceptional 
 
80 PRINCIPLES AND PRACTICE OF 
 
 but of common occurrence. * In new Levees such an imposition 
 can always be detected after rains by vertical holes in the 
 crown and sides ; and in dry weather may be detected by 
 piercing the Levee at intervals along the crown with an iron rod. 
 The only certain means, however, of excluding from the Mis- 
 sissippi embankments the materials grubbed and cleared from 
 their base, is the enforcement of the rule that those materials 
 shall have been burned in the presence of the superintendent 
 before the bank shall be commenced. 
 
 In connection with this subject it may be observed here, 
 that the clearing along the line of Levee ought to extend to all 
 trees growing within their own respective lengths on either 
 side of the crown of the Levee. All trees without that distance 
 ought to be cut dawn ; but if this should be supposed a need- 
 
 * The Coahoma Commissioner who has made himself thoroughly conversant 
 with the scientific principles and practical facts of Levees in bearing testimony to 
 the triumphant success during the late extraordinary flood of Levees properly 
 planned and executed, calls attention to the cause of breaks being Logs, &c., in the 
 bank. In his printed Address, of the 25th last July, that gentleman holds the fol- 
 lowing language: "The question, then, is: did the Levee when properly built per- 
 form the work for which it was declared competent 1 I say it did ; and challenge 
 any man upon the whole line of Levee, on either side, to point to a single break where 
 there did not exist a local cause." The address goes on to say : " But in the large 
 majority of cases where breaks occurred, the water either ran over the top, or 
 stumps and logs embedded in the work occasioned the break." 
 
 One of the most general causes, however, of Levee-breaks during the late floods, 
 has been the Craw-fish. This animal digs a hole through the Levee, from the water 
 side, in order to obtain a passage through the small fish, or water insects passing 
 in with the flow, furnishing the object and the reward of his labor as prey. In sand, 
 the Craw-fish cannot carry out his purpose, for the hole when made falls in, the 
 Craw-fish, accordingly, desisting in his work. Clay banks are well adapted for the 
 operations of the Craw-fish, and though, essentially the best in all other particulars 
 for Levees, are open to this grave objection ; this fact suggests that to obtain the 
 general advantages of clay embankments in Leveeing, it is expedient in order to 
 guard against its special disadvantages in those works, to carry up within them a 
 wall of sand. The experience of the late flood makes this sand-wall in clay Levees 
 a detail of the first importance. 
 
EMBANKING LANDS FROM RIVER-FLOODS. 81 
 
 less precaution, it certainly is not so in the case of all such 
 trees leaning in the direction of the Levee. This should be 
 done during the clearing of the ground for the Levee, the 
 trunks to be burned with the rest of the clearing-spoil. During 
 high-water the falling of a tree, from either side, across the 
 embankment, will cut down through the crown at least several 
 feet. I have known one instance where a large cotton-wood 
 (4J feet in diameter) cut a 5J feet Levee to its base. If a simi- 
 lar cut should occur during the flood season, on a high Levee, 
 the water admitted through the gap so made would form a 
 crevasse, sweeping away large lengths of the Levee, inundating 
 the adjoining plantations, and for the season of its occurrence, 
 destroying the object of the whole system of Leveeing to the 
 people and property of hundreds of square miles. But, besides 
 the avoidance of this danger, the removal of those leaning 
 trees, at first, is in fact less expensive than when they have 
 fallen. 
 
 Road-crossings are very frequently cut across Levees, in 
 Mississippi, and elsewhere, during low-water. The planter 
 immediately concerned is expected to see, at the proper time, 
 that such a cut is duly filled ; but in some stretches of Levee, 
 it often occurs that what is every body's business is no body's. 
 Besides, this liberty with the Levee is bad in principle ; for 
 it points directly to impunity, for infringements on the sanc- 
 tity so to speak of the work in less dangerous particulars. 
 Rows of Osage-Orange, or other hedge-shrub set along the base 
 of each slope, will save the embankment, better than all the 
 restrictions of law, from injury by either manor beast. In the 
 absence of these hedges, however, it may be suggested that, 
 to guard against the cutting of roads across the Levee, the 
 best course would be, as in Holland, to raise the natural surface 
 of the road-way by embankment from each side in easy slopes, 
 to the top of the Levee. To slope down the Levee-level at a 
 
 rate of even 20 to 1 to the level of the road on either side 
 
 6 
 
82 PRINCIPLES AND PRACTICE OP 
 
 crossing it, will, in general, require comparatively little work, 
 the ba&e of such an extra bank, exclusive of one-half the base 
 of the Levee, being for crossing a Levee of 10 feet high, but in 
 all some 370 feet. This road-way is, in Holland, termed " Ramp." 
 The cost of this extra work is but small for securing the advan- 
 tage of placing the continuity of the Levee beyond the acci- 
 dents of local carelessness of placing the important principle 
 of its inviolability beyond the infringement of popular necessity. 
 
 Levees across creeks or bayous are very often made wide 
 enough on top to constitute a roadway. The inviolability 
 of the Levee comes in here again to object as an important 
 principle against this practice. Besides that the course is 
 objectionable on the ground of economy. The grassing of the 
 crown as a saving of wear and tear is, with the supposition of 
 the roadway, out of the question. If cattle-trespass on the 
 slopes is to be excluded, it can be excluded with a roadway on 
 the top by only the cost of four instead of two rows of hedges, 
 two on each side of the roadway and two along each slope. 
 The wear and tear of the whole Levee with the rut-cuttings of 
 wheels in wet weather, and the slope-breakings of horse-hoofs 
 in wet and dry weather, would make this roadway tell heavily 
 on the Levee-account in increased outlays for maintenance. 
 These objections apply with equal force to employment of 
 Levees for roadways, whether along their whole length or for 
 any part of that length. In the case of bayou crossings, or 
 the crossings of other deep breaks in the general surface of 
 the back-land, the roadway may be combined with the Levee 
 without going to the extent of making them perfectly identi- 
 cal. The following section shows a method of combining the 
 roadway with the Levee at deep-crossings with, in general, 
 less work a method, too, removed from the objections urged 
 above against using the crown of the Levee for the purpose. 
 
 The Levee here is assumed to be protected fully from tres- 
 passers by the hedge-rows shown at a and 6, the whole surface 
 
EMBANKING LANDS FROM RIVER-FLOODS. 
 
 intermediate between these being protected by the proper 
 coating of grass. The roadway, of course, is situated on the 
 dry side, and as an extra to the Levee, may be left to the par- 
 ties concerned in it as a road for its maintenance. Three- 
 fourths of it may be washed or worn away without any incon- 
 venience to the Levee. Improvements of this sort on the 
 present practice must be regarded with the consideration due 
 to everything pointing to a saving in public outlay in taxation. 
 The general question of making Levees the site of the road- 
 ways required for the traffic and travel taking their direction, 
 is met in the foregoing remarks on Levee roadways. The 
 gravest objection, as has been seen, applies to the location of 
 roads on drainage embankments. Occasional travel even is so 
 injurious that it ought to be avoided by all means where 
 more efficient means are not employed by the collection of 
 brush, briars, or other obstacles across the whole extent of the 
 bank at intervals. These impediments are absolutely essential 
 in new works on new locations ; for few men will be so scru- 
 pulously observant of law as to ride through the tangled paths 
 of a swamp when they may choose, in their stead, the open and 
 unbroken smoothness of a Levee. The enforcement of penal- 
 ties, under such circumstances, is difficult. The best remedy in 
 all such cases, after that of impervious hedge-rows, is and for 
 travel and traffic only, it is a perfect remedy the construction 
 of a roadway within the Levee at a distance sufficient to save the 
 berm from the contingency of encroachment by either hoof or 
 tyre. This, with brush walls drawn across the bank at inter- 
 vals, will save the Levee from all damage except that arising 
 from the trampings of cattle and the " rooting' 7 of hogs. The 
 Osage-Orange, however, is infinitely better than an army of 
 police and a volume of penal laws, for the protection of em- 
 bankments from all trespass. 
 
84 PRINCIPLES AND PRACTICE OP 
 
 Excavations of the ground outside a Levee is objectionable. 
 In sandy or other weak earths it is even worse so than in clays. 
 Under any circumstances such cuts ought to be removed as 
 far as possible from the berm of the Levee ; but never less 
 than ten feet. The " pits" dug in such positions ought not to 
 be continuous ; but ought to be divided from each other by 
 walls preserving the continuity of the natural surface. Separ- 
 ated thus from each other, those excavations will fill up the 
 sooner under the depositions of floods. These breaks in the 
 external cuts will also prevent them of becoming channels of 
 flow ; and thus guard against the creation of avoidable current 
 washes on the slope and berm of the embankment. The slope 
 of those external pits should, on the side next the toe of the 
 Levee, never be vertical, but always dressed off at an angle 
 fully equal to that of the adjoining Levee slope. Left at a 
 less slope, the pit-banks may fall in, and the falling so occurring 
 will then advance until finally it shall have undermined at 
 least a portion of the Levee itself. Trifling as this detail may 
 appear, it is urged here as one which practical experience has 
 pointed out as of great importance. Exterior excavations, 
 then, for the construction of Levees should be made in pits 
 separated from each other at intervals by walls, the inner 
 slopes of these pits being never nearer the Levee base than ten 
 feet, and never of a more rapid angle than that of the water- 
 slope of the adjoining Levee. These precautions ought to be 
 laid down expressly in Levee-contracts. Carried out practically 
 they will save the work from the contingencies of its first and 
 perhaps second year of trial ; but after that, the foreshore 
 the ground outside the Levee will " warp" or " silt up" under 
 the flood-deposits until the resulting elevation going on to the 
 full height of high water mark, the foreshore side of the em- 
 bankment will cost little or nothing for maintenance. 
 
 Large Levees require in their construction especial care. 
 As a general rule it may be observed of those works that the 
 
EMBANKING LANDS FROM RIVER-FLOODS. 85 
 
 heavier they are the weaker is their natural foundation. The 
 twenty or thirty feet Levee in all cases within my observation 
 implied a Levee, whether across swamp, bayou, or " old bed," 
 having for its base a soil no stronger than shifting sands or 
 watery puddle. All such Levees, on this consideration and on 
 the further consideration of proper compactness and strength, 
 ought to be carried up in regular layers of earth, each layer 
 " dished'' out from the centre and tramped over by the hauling 
 necessary for the next succeeding layer. These layers should 
 not exceed three feet in thickness. Crusts thus carried up 
 one after another from the base, assist to distribute the press- 
 ure of the whole equally over the whole base ; and thus in the 
 case of weak foundations assist largely in the stability of the 
 work. Hollowed out from the centre " dished" these layers 
 or crusts of tramped earth fitting each into the one below it 
 cannot shift under the lateral strain of high-water. After en- 
 suring safety at first by carrying the bank up thus in layers, 
 the whole becomes subsequently one solid and settled mass. 
 The settlement allowance in banks so constructed is merely 
 nominal. In connection with the stability of Levees across 
 ow-discharging bayous, it may be observed here, that that 
 stability is sometimes threatened, after all proper precaution 
 in construction, by the accumulation of water on their inner 
 side. The bayou having discharged outwards a mere trickle 
 perhaps at the time of stopping it, soon accumulates to a con- 
 siderable body of water, until finally the whole becomes 
 ponded up against the sides and bottom of the bayou and the 
 inside slope of the Levee to the height of the bayou bank. 
 The additional load on the foundation over and above the 
 Levee and the river flood-water, is in itself objectionable, 
 though perhaps not quite so much so as might appear at first, 
 when it is recollected that the distribution of the weight, front 
 and rear of the Levee, would save the danger of " bulgings" 
 up at the toe of the Levee the place of these bulgings being 
 
86 PRINCIPLES AND PRACTICE OP 
 
 always occupied by corresponding sinkings of the embank- 
 ment. But the greatest objection of such pondings up is their 
 continuance ; seeing that the longer they continue the more 
 thorough and the deeper is the saturation of the underlying 
 earths ; and the more thorough and deeper their saturation 
 the greater the extent and the degree of the weakness or 
 " meltings" of the earths in the foundation of the Levee. In 
 order to guard against this evil, it is necessary that small cuts 
 be run up through, or out of, such bayous to such a point as 
 may be necessary to divert their drainage into the general out- 
 fall of the surrounding country. All Levees across ottf-flow 
 creeks or bayous have been observed, when this precaution 
 has been neglected, to sink into their foundations ; and as a 
 consequence to cost more than otherwise for their maintenance. 
 Crusts of earth have been referred to already as means for 
 the distribution over a wide surface, of superincumbent loads. 
 In the case of a " muck ditch ." cut along the site of the Great 
 Yazoo Pass-Levee of 1855 cut against the express direction, 
 if memory serve me truly, of the Commissioner and the Engi- 
 neer the advantage of an unbroken crust of this sort was 
 illustrated very strikingly. The division by the " muck ditch" 
 having taken place under the line of greatest load, that load, 
 pressing on the lips of the cut vertically, acted on them as re- 
 marked in such cases on a previous page, with a leverage, until 
 driven down step by step the crust must have become, by the 
 consequent bending, broken near the toe of the Levee on each 
 side. Two distinct pieces of crust were thus, in all probability, 
 driven down angularly into the thin matter underneath ; and 
 thus, instead of using every precaution to preserve the natural 
 crust as a grillage under the bank, the Levee was left to seek 
 its foundation as best it might amongst quicksands and fluid 
 puddle. The weakness of the foundation told itself accord 
 ingly by not only the sinking of the crown of the embankment, 
 but also by the bulgings of the slopes and the spreading of the 
 
EMBANKING LANDS FROM RIVER-FLOODS. 87 
 
 base " a corduroy " or causeway of logs near the inner talus 
 having been forced by those spreadings from a straight line 
 into a succession of zig-zags. Alarmed by the sinkage of his 
 work a sinkage that, according to his estimate, was made 
 naturally enough by one in such a position, to cover all the losses 
 consequent on his own mismanagement the contractor became 
 unmanagable. The Engineer recommended him to open a 
 ditch of a few feet wide and of five or six feet deep inside and 
 parallel with the Levee, in order, by filling up the same with 
 the trunks of the young cotton-woods cleared from the base of 
 the Levee, to present a breast work of equally bearing resistance 
 on the dry side to the spreadings of the base the then-standing 
 flood-waters on the wet side offering sufficient resistance to 
 spreadings or bulgings on the wet side. A deep pit of sand 
 furnished convenient drainage for the ditch so suggested ; and 
 the excavations of the ditch would have been available for the 
 completion of the embankment according to the contract. 
 Instead of adopting this course, how r ever, the contractor at- 
 tempted to carry up the sinking Levee to the contract-height 
 by removing the masses of earth bulged out on its sides and 
 spread out beyond its base to the crown, heedless of the re- 
 monstrance of the Engineer that in doing so he was merely 
 revolving an endless chain. Every yard taken from the 
 bulgings on the side and removed to the sinkings on the top, 
 was speedily replaced by another yard on the sides, the top 
 remaining in statu quo. Finally, however, the work was re- 
 sumed at the base and carried up in closer conformity with the 
 slopes ; and, all parts of the cross-section thus newly loaded, the 
 crown carried up finally in " a comb" to exclude the flood then 
 standing some 20 feet on the water-slope, the whole presented 
 sufficient solidity, under all the unfavorable circumstances that 
 attended its construction, to have dammed back that year's 
 flood. This case fell within the practice of Mr. M. B. Hewson. 
 Another case of weak foundation for a Levee came under the 
 
88 PRINCIPLES AND PRACTICE OP 
 
 observation of that gentleman in the construction of the great 
 Levee across the mouth of the Old Lake of Oldtown, in the 
 State of Arkansas. The site of this Levee had, within the 
 memory of men living in the neighborhood, been the bed 
 of the Mississippi River ; and as such may be well supposed to 
 have presented a foundation of a description the very weakest. 
 A shallow stream running across the proposed line of work, the 
 undertaking had not the advantage in some places of even the 
 hard crust of the Yazoo Pass. The irregular course pursued in 
 carrying out those works on the Mississippi confines generally 
 its restriction on the contractor to the height, width at base, 
 and width of crown, the means by which he fulfills those con- 
 ditions being questions for only his consideration. Acting on 
 the part of the State, Mr. Hewson had no voice as to foundation 
 or any other obvious preliminary in a proper construction of 
 the work. The contractor accordingly dumped in his earth 
 without any preparation of the foundation ; and counting on 
 pay for every yard so dumped, carried up the work by, simply f 
 force of purpose and labor. The centre frequently sank into the 
 foundation. Standing sometimes for a couple of hours at its 
 full height, it would drop down suddenly from 5 to 10 feet. The 
 base spread to an incredible extent at all points but one that 
 one being loaded heavily with an interlocked and tangled mass 
 of logs, branches, and trunks, removed in clearing the site of 
 the work. The spreadings having reached their utmost at all 
 other points, the work was being carried up along the loaded 
 length of the slope, when suddenly the tangled mass of timber 
 loading it was torn asunder with a loud noise, and shot for some 
 distance from its original position. The bulging that took the 
 place of this weight on the base of the Levee was found by 
 measurement to have been some 4000 yards ! Such are the 
 forces exerted by such Levees ; and such the character of their 
 foundations. The " sinkage," as it is locally termed, was, how- 
 ever, in the case of the Yazoo Pass-Levee, a mere trifle in com- 
 parison with that at Oldtown. 
 
EMBANKING LANDS FROM RIVER-FLOODS. 89 
 
 Weak foundations occur in the case of Levees, in only the 
 cases of those important works that may be considered the 
 Keys of the whole. The Yazoo Pass embankment once swept 
 away, the whole extent of Levee remaining in the County of 
 Coahoma would become, virtually, valueless to the parties 
 living behind it as a protection from inundation. The under- 
 taking of the Levee-system at all, involves, therefore, the 
 necessity that all those more important points of the system be 
 executed in a manner to insure, at least, as high a degree of stabil- 
 ity as any of the less important parts of the system. With some 
 30 feet of water standing on its outer slope at flood-time, its inner 
 slope resting on the bed of a channel, of like depth, constitu- 
 ting the arterial drain of the back country, the failure of one 
 of those Key-works of the system, when occurring to even the 
 smallest extent, involves its total destruction. The rush of 
 water through the whole width of this Key-levee, under a 
 head of some 30 feet, sweeps into the back country in a foam- 
 ing torrent ; the whole system of back drains becoming, in the 
 first place, suddenly charged to the lips ; and then, all the 
 overflow passing off upon a surface deprived of out-fall, the ' 
 country behind the Levee becomes, to a greater or less extent 
 according to duration of the flood-level in the river, com- 
 pletely deluged. On the other hand, a " crevasse," or breach 
 in the general line of the Levee, may not only be stopped 
 altogether before it arrives at any considerable width ; but at 
 the worst, the depth of its out-flow not exceeding a few feet, 
 the back lands pass off the water, through their system of back- 
 drainage, at a rate, if not even quite as rapid as the in-flow, 
 quite rapidly enough in the generality of cases to prevent the 
 engorgement of the back-drains before the fall of the river- 
 level. A breach in the Key-levees, then, involves a certainty 
 of wide inundation ; while a breach in a less important part of 
 the system leads to an inundation under the worst circumstan- 
 ces, limited in its extent, and in its duration brief. But this 
 
90 PRINCIPLES AND PRACTICE OF 
 
 is not the only reason why it becomes necessary to con- 
 struct Key-levees with special care. Costing, according to 
 their present mode of construction at a rate so high, in some 
 cases, as upwards of $60,000 a mile, whereas, the generality of 
 Levees do not cost over $2,500 a mile ; a breach in one of those 
 heavy works leading as it always does to its total demolition, 
 results in a very serious loss of money. The destruction of 
 Yazoo Pass -Levee was as great an injury to the treasury of 
 Coahoma County as would have been the destruction of the 
 whole embankment, from the junction with the Pass-levee to 
 a point as far South as Friar's Point ! The Commissioner was 
 very much censured by parties interested in the stability of 
 this Pass-levee, for his special outlays on construction of this 
 work, and for his rigid enforcement of the conditions set forth 
 in the contract for securing that stability but how thoroughly 
 rebuked his short-sighted, and, perhaps, factious censurers 
 must have felt, when they discovered to their cost, by the des- 
 truction, in 1855, of that most important work, that in all his 
 care and all his " harshness," Col. Alcorn was pursuing the 
 course as a public servant, of courageous honesty and enlight- 
 ened carefulness. The truth is, Col. Alcorn felt at the time, 
 that his duty in the case of the Pass-levee was rather under- 
 done than overdone ; and in conversation with Mr. M. B. 
 Hewson, on the subject, frequently referred to the embarrass- 
 ment in which he was placed in the case, by the absence of a 
 sound and intelligent public opinion as to the conduct of those 
 works. The purse-strings being in the hands of the tax-payers 
 in the case of Levees, it is of importance to their best interests 
 to place such measures as are necessary for the proper con- 
 struction of those works, under the endorsement of their 
 understandings. Having with this view referred to the special 
 importance of such works as the Yazoo Pass-Levee, and the 
 Old Town-Levee, &c., it is proposed, now, to offer some general 
 remarks on Levee-foundations. 
 
EMBANKING LANDS FROM RIVER-FLOODS. 91 
 
 The more important portions of the system of river-embank- 
 ment in the case of the Mississippi, rests, as has been said, on 
 foundations of puddle or quicksand. Continuing to dump in 
 earth into embankments ~on such a foundation, is found in 
 practice to result, after a greater or less waste of earth, in 
 compressing the foundation downwards and outwards to a 
 compactness sufficient for the resistance necessary to sustain 
 the intended Levee. The Levee accordingly stands its height, 
 crown, and side-slopes being in perfect accordance with the 
 contract. This is all the public expect ; and unfortunately, 
 with their present views, this is all they will sustain their 
 Commissioner in enforcing. The flood, however, rises on the 
 face of this Levee 10 feet, 15 feet, 20 feet even 25 feet, and 
 a load of 600 Ibs., 900 Ibs., 1500 Ibs. becomes thus added to 
 every square foot of the outer half of the Levee base ; while 
 no corresponding weight on the inside is available for estab- 
 lishing a counterpoise in the watery material of the foundation. 
 The compression that the foundation underwent, originally, 
 before the Levee attained the required height, was the result 
 of the weight of the earth employed in its construction ; and 
 it is only reasonable to infer that, with the same foundation, a 
 further load, whether of earth or of water, will occasion a fur- 
 ther compression. Additional sinking, or " canting" under the 
 outside slope, and additional bulging, or spreading of the inside 
 slope, is a natural result under such circumstances ; and the 
 special weakening of foundation under the special saturation 
 of a superincumbent head of water, combining with the other 
 natural result in the case, no surprise ought to be felt that the 
 great Levees, constructed after the general practice on the 
 Mississippi, should be swept away before high floods. To con- 
 struct those works properly, then, requires special steps in 
 reference to the strength of their foundations. Brush makes a 
 very good foundation in weak soils. McAdamized Roads have 
 been carried through otherwise impassable marshes in England, 
 
92 PRINCIPLES AND PRACTICE OP 
 
 on foundations of brush laid in considerable thickness upon 
 the surface of the marsh. It is extensively used in Holland, 
 and the " Low Countries," to strengthen the foundation of 
 heavier embankments than are likely ever to occur in practice 
 upon the Mississippi bottom. In Ireland, heavy embankments 
 of the Grand Canal, and also, embankments of the Great West- 
 ern Railroad have been carried in several instances across deep 
 " flow-bogs" on brush. The Grand Trunk Railroad, of Canada, 
 has a bank some thirty or forty feet high, across a deep and 
 wide marsh, sustained by a brush foundation. Several such 
 instances of the use of brush might be mentioned here, to show 
 how useful for the purpose of Levee-foundations is a material 
 that, along the banks of the Mississippi, may be obtained with- 
 out stint or trouble. The branches of the trees cut off for the 
 purpose, should be laid evenly across the base of the Levee, in 
 layers 24 inches thick, the direction of those in each layer " ang- 
 ling" across the line of the base, those of the layer next above 
 being laid " angling" in the other direction. Two layers are quite 
 sufficient for ordinary heights of bank, and ordinary weakness 
 of foundation ; but in other cases, it were better to lay three 
 layers or even four. " Old beds," such as the Yazoo Pass, or 
 Old Town Bayou, should in all cases be brushed. with four lay- 
 ers, compressible to a thickness of, at least, six feet, each layer 
 having its branches laid across the line of Levee, askew the 
 second layer crossing that of the first, and so, also, with the 
 others. The brush should be cut off regularly, so that it would 
 never extend on either side within ten or twelve feet of the 
 toe of the bank ; pressed for even its own thickness into the 
 foundation, and the brush covered up completely, the embank- 
 ment resting upon it will not, necessarily, be open to the 
 objection of leakage. Brushing, properly and carefully em- 
 ployed, in even the highly unfavorable circumstances of the 
 Key-works of the Levee-drainage, will constitue a perfectly 
 stable foundation. Fascines are sometimes employed in the 
 
EMBANKING LANDS FKOM RIVER-FLOODS. 93 
 
 foundations of embankments ; but, while much more trouble- 
 some, are not so efficient as simple brushing executed properly. 
 Fascines may be described as small bundles of brush, each tied 
 firmly like a birch-broom. These are laid down one row across 
 the other for foundations of banks ; but all the advantages of 
 their compactness may be secured in brushing, by selecting 
 the brush carefully in the first instance long, straight, tough, 
 and sufficiently light and in the next instance, pinning it 
 down occasionally by wooden forks to the ground in the first 
 case, and to the layer below it, in the next. More perfect 
 continuity latterally and longitudinally may be obtained with 
 the simple brush than with the fascines. Sand is another 
 material most available along the Mississippi, for the purposes 
 of artificial foundations. Loose in its parts as it is, sand is 
 not supposed, generally, to be capable of constructing a mass 
 of such stiffness as to distribute over its length and breadth 
 the pressure of a heavy load* This, however, is the fact. Like 
 water in other particulars, it is especially like water in dis- 
 charging its pressures, under certain circumstances, latterally 
 as well as vertically. This property of sand has lead to its 
 employment in foundations as a substitute, in certain cases, 
 for piles of wood and of iron. Wooden piles obtain their bear- 
 ing mainly from the resistance presented to their section ; but 
 sand-piles, in addition to this resistance, are found also to 
 present a further resistance along their sides. Friction or 
 adhesion, as it may be, this increased sustaining power of the 
 sand-pile has been found highly useful in the preparation of 
 foundations for heavy Engineering works in soft and deep 
 alluvium. Where the base is not so weak as to require the 
 use of piles, artificial foundations of ample strength are some- 
 times obtained by spreading over the natural surface a thick 
 and uniform coating of sand. In wet situations, however, 
 hydraulic lime is sometimes added under this practice to the 
 extent of one-seventh the bulk of the sand ; and as such an 
 
94 PRINCIPLES AXD PRACTICE OF 
 
 addition would, in all likelihood, be found necessary in the case 
 of the great embankments of the Levee-system, the use of sand 
 for artificial foundations for Levees, must, on the score of econ- 
 omy, be confined to piling. Brush, however, is in all cases 
 the best material available along the Mississippi, for the pre- 
 paration of a Levee-base ; but before .loading an unusually 
 weak base with an unusually heavy embankment, it would be 
 well, in addition to the brushing, to sink one row of sand-piles 
 immediately under the intended site of the crown, and two 
 other rows on each side of it, the piles in each row alternating' 
 regularly with those next it, thus : 
 
 These piles ought to be about from 1 to 2 feet in diameter, 
 the centre row being placed at intervals from centre to centre 
 of say six feet, the next row on each side being parallel with 
 this centre row at a distance from it from centre to centre 
 of about 8 feet, the intervals between the piles of those second 
 rows being from centre to centre 8 feet. The outside piles 
 ought to be sunk at a distance from each other and from the 
 adjoining rows of 10 feet from centre to centre. These piles 
 may be put in by several methods. A light lift-ram being em- 
 ployed to drive into the intended place (where .the same may 
 not be done by a heavy sledge) a Avooden pile of the intended 
 size, this pile, after being thus sunk to the required depth, must 
 be withdrawn, and the hole filled in rapidly with sand for the 
 purpose, this sand-filling being compressed at intervals as it 
 
EMBANKING LANDS FROM RIVER-FLOODS. 95 
 
 progresses, by blows of a rammer. By the time this sand pile 
 is thus filled in and compressed, the driving-party will have 
 been placed ready for work at an adjoining pile ; and thus the 
 whole area will be piled, each pile being completed before the 
 driving shall have been commenced for that adjoining it. Six 
 or seven feet is quite sufficient as a depth for those sand-columns. 
 The best method, however, for sinking those piles where the 
 extent of the work would justify the outlay, would be by an iron 
 cylinder, furnished on the inside with screw threads one-half 
 the diameter in width ; for this might be sunk and raised 
 without machinery ; and permitting conveniently of increased 
 size, is well adapted to piling with sand columns of two feet in 
 diameter. The larger and the closer the sand piles the more 
 thoroughly do they pack the material of the base, and the more 
 effectively do they increase their own bearing-strength. The 
 regular mode for sand piling is that pointed out here ; but the 
 rough mode of doing every thing in Leveeing will probably 
 substitute, in sinking those piles, a pole forced into the ground 
 by manual strength, and, in withdrawing it afterwards, worked 
 around its point until the hole becomes sufficiently widened. 
 The bottom of the pile, it must be recollected, will be very small 
 under this proceeding ; but by ramming the sand thoroughly 
 into the hole water or no water sand-piles will, under even 
 such poor construction, assist largely in compressing the soft 
 earth around them, and in supporting the load of a heavy em- 
 bankment. Be the mode of construction for those piles then 
 what it may, they are recommended in all cases of unusually 
 heavy embankments and unusually weak earth ; and when even 
 partially employed are highly valuable accessions to " brushing " 
 in artificial foundations. The popular understanding must, how- 
 ever, be satisfied in reference to every reform in the con- 
 struction or management of Levees ; and as the association of 
 strength with a " foundation of sand " conflicts with all the 
 previously formed views of that popular understanding, it is 
 
96 PRINCIPLES AND PRACTICE OP 
 
 well to sustain the use of sand-piles as has been done in the 
 case of the recommendation of brushing by reference to 
 specific practical tests. In reference to the general fact of 
 sand being a strengthener of weak foundations, it may be ob- 
 served that it has been employed successfully as such, under 
 heavy masses of masonry at Geneva in Switzerland, at Bayonne 
 and Paris in France, in India, in Surinam, and doubtless in many 
 other places where its use has not fallen within the knowledge 
 of the writer of this. In the " Annales des Fonts et Chausees " 
 the Reports of the Board of Public Works of France for 
 1835, a complete account of the use of sand in foundations is 
 published ; and in order to satisfy the sceptical planter as to the 
 utility of that material in foundations, the following extract is 
 made from that report in the translation of a professional paper 
 on the subject, by a member of the British Corps of Royal 
 Engineers. " On a very soft soil nine piles about, 4 feet three 
 inches long and 8 inches in diameter, and distant from centre 
 to centre about 16 inches, were driven with a monkey weighing 
 about 2 cwt. falling from a height of 3 feet 6 inches ; the 
 driving was continued till the piles only yielded about \ of an 
 inch at a stroke ; upon these piles a load of 20,000 Ibs. was 
 placed and the settlement amounted to about one-fifth of an inch. 
 These nine piles were then drawn j and the holes in the soil 
 filled in with sand ; 16 more piles were driven in the same way 
 so as to occupy a space of 6 feet square ; the ground was then 
 well rammed ; and a mass of masonry similar to that in the 
 former experiment was built and loaded with lead as before : 
 
 Under a weight of 1050 Ibs. the settlement was 1-25 inch. 
 " 2100 Ibs. " " 2-25 inch. 
 
 " 3150 Ibs. " " 8-25 inch. 
 
 Which increased to 4-25 inch. 
 
 Under a load of 18 tons the settlement was 1-5 inch. 
 21 tons made no sensible change, and 30 tons 
 increased the settlement about 1-50, and 
 after a month the total amounted to 3-5 inch. 
 
EMBANKING LANDS FROM RIVER-FLOODS. 97 
 
 A wall about 12 feet deep filled up with silt and clay ; after 
 having removed about 16 inches of soil from the surface the 
 under stratum was found quite soft, a Ram penetrating 6 
 inches at a stroke. To harden this soil, 25 piles were driven 
 about 4 feet 6 inches long each ; this forced the soil up about 
 16 inches above the previous level ; the driving was continued 
 till 20 blows of a Ram weighing 2 cwt. let fall from a height of 
 3 feet only, caused a pile to penetrate about 4 inches, which 
 took about 40 minutes' work. After having driven all the 25 
 piles and levelled their heads, they were loaded as follows : 
 
 12 tons caused a settlement of about 1-20 inch. 
 18 tons " " 1-10 inch. 
 
 And in three days this increased to 1-5 inch. 
 
 These piles were then drawn, and the holes filled with sand, 
 which was well rammed, and which ramming caused a barrow 
 full of earth to bulge up between the holes. On the ground 
 thus prepared a mass of masonry was constructed and loaded 
 with lead as before, and the settlement was as follows : 
 
 15 tons caused a settlement of 1-10 inch. 
 29 tons " " 2-5 inch. 
 
 These weights were placed in April and remained on till De- 
 cember, when the increased settlement amounted to f of an 
 inch. The load being reduced to 10 tons, no further settlement 
 took place between December and May." Other cases of the 
 employment of sand-piles are given in the same reports ; but 
 this is sufficiently specific and forcible to satisfy any reasonable 
 doubt as to that employment in the foundation of Levees. 
 Some of the cases given have been in situations where the silt 
 and alluvium was over sixty feet in depth. Let the holes then 
 be opened as they may, pack them well with sand as close to 
 each other as the circumstances of the case may demand ; and 
 the result will be, in all cases, an accession to the strength of 
 
 the foundation, and, therefore, to the stability of the Levee. 
 
 7 
 
98 PRINCIPLES AND PEACTICE OF 
 
 Brush and sand combined will undoubtedly sustain the heaviest 
 Levee under even the most unfavorable circumstances ; and 
 the most available and cheapest materials for the purpose 
 being thus sufficient for the requirements of any case, it is un- 
 necessary to consider any other methods than those based on 
 the use of these for accomplishing that important object in 
 Leveeing, substantial foundations. 
 
 The difficulty, however, of meeting every particular of im- 
 proved construction in the Levee, lies in the sneer of the 
 purse-holders in the case at what it calls " College" Leveeing. 
 But the taxpayer who is enriched by the Levees of the Missis- 
 sippi will make a grave mistake in assuming himself exempt 
 from the hard lessons that have taught people placed under 
 like circumstances in other countries, the wisdom of their pres- 
 ent practice in water-embankments. In order to urge on the 
 popular judgment of the valley the importance of the sugges- 
 tions made .above for fencing, grassing, and otherwise 
 protecting the work, after its construction, for mucking, layer- 
 ing, brushing, and even piling, in the course of its construction, 
 it may be well to add here a few instances of the costliness and 
 care involved in the case of European and Asiatic water-em- 
 bankments. Touching the dimensions recommended above, it 
 may be observed that Sir. Cornelius Vermuyden gave the em- 
 bankments of the Welland in England for a height of 8 feet, a 
 base of 70 feet ; and that of the Ouse with a crown of ten 
 feet for a height of 8 feet, a base of 60 feet. The Ouse at 
 Weisbach has for its embankment a height of 10 feet carried 
 up on a base of 100 feet. Sir John McNeill, in the drainage of 
 Lough Swilly in Ireland, gave his embankments a base of from 
 5J to 6 feet for every foot of their height. On the Lower Da- 
 moodah in India, the " Bunds," as " Levees" are there termed, 
 have a base for 4 feet high of 23 feet. In reference to the 
 inequality recommended in the case of the dry and the wet 
 slopes of Levees, it may be added that the practice of this 
 
EMBANKING LANDS FROM EIVER-FLOODS. 99 
 
 inequality is universal. Sir John McNeill a name distin- 
 guished highly in his profession has given the Lough S willy 
 embankments, already referred to, an outside slope of from 
 
 3 to 1 to 4 to 1, while the inside slope is but 2 to 1. 
 
 Sir John Rennie reports the construction of an embankment 
 in connection with the Commissioners of the Nene Outfall, the 
 dimensions of which were 5| to 1 to seaward, 3 to 1 to landward, 
 the top being 4 feet broad. Arthur Young, in his agricultural 
 reports, mentions several cases of embanking, one of which he 
 says was erected in 1800 : the dimensions were for the sea slope 
 
 4 to 1, land slope 2 to 1, 12 feet in height and 4 feet broad on 
 top. The Dikes of Holland constructed principally as defences 
 from the sea are generally raised 30 feet above the ordinary 
 level of the country. Banks have been occasionally made twelve 
 feet wide on top, and carried 2 feet above the high-watermark, 
 they were in some positions turfed and strengthened in 
 various places with stakes, or piles and planking. Sometimes 
 banks were formed by driving rows of piles or stout stakes 
 parallel to the river at distances of from 2 to 3 feet apart, and 
 after uniting their heads by a plank, or weaving rods around 
 them, the parallel spaces between were filled up with chalk 
 or some other hard substance. Banks made of sand, in which 
 twigs of brush-wood are placed horizontally and clayed properly 
 with from 1 to 2 feet thick of clay, are found to stand remark- 
 ably well. Coroboratory of the stress laid upon the selection 
 of clay for Levees, it may be observed that in Holland, where 
 the system of water-embankment is carried out under all the 
 experience of centuries of disaster and destruction of life and 
 property, and where the adoption of the best mode in each 
 particular is a question of national concern, sand in the site of 
 the Levee is rejected when better material cannot be obtained 
 short of a haul of even Jive miles. In Europe, no trouble or cost 
 is spared in the construction of water-banks to make them 
 perfectly water-tight. Carrying up within the work a wall of 
 
100 PRINCIPLES AND PRACTICE OF 
 
 puddle, a practice which is known by every Engineer to be 
 universal in the construction of all water-tight embankments, 
 does not require for its endorsement an isolated instance like 
 even that in the banks of the S willy-drainage in the practice 
 of Sir John McNeill. The care recommended in reference to 
 the foundations of Levees is borne out by general usage in such 
 works in England, in Ireland, in France, in Holland, in Ger- 
 many, in India. The preservative measures urged above are 
 but modifications based on universal practice. In England and 
 in France water-banks are regularly " turfed ;" and in weak 
 places protected with even stakes and piles. In Holland the 
 water-banks are protected on the outside by a strong coating 
 or matting of Saggers and reeds ; and on the inside are sus- 
 tained by piles and planking, the slopes being coated thickly 
 with grass. In the Swilly works, as illustrating the latest practice 
 and highest experience in Europe, it may be remarked that the 
 land-slopes of the embankments were all covered with turf ; 
 the water-slopes having been protected with a facing of fascines 
 six feet thick at bottom and 4 feet thick at top, these fascines 
 being laid in an oblique direction in the slope and fastened 
 thereto firmly by forks of iron. Reason then has been first 
 appealed to herein urging the adoption of the care recommended 
 in the construction and protection of Levees; and these last 
 references to the subject, show that the suggestions of reason 
 in the premises, are fully endorsed by the general practice. 
 But another point for viewing the subject may be illustrated by 
 a reference to the cost of ^Levee-maintenance. In Zealand the 
 maintenance of their embankments 300 miles in length cost 
 them annually $800,000 ! The maintenance of the embankments 
 and the regulation of the water-levels in Holland, cost the 
 enormous sum of $3,000,000 a year ! Sea-banks those works in 
 both Zealand and Holland chiefly are ; but, on the other hand, 
 it must be observed that in reference to the cost of their main- 
 tenance they have been constructed with the best material in 
 
EMBANKING LANDS FEOM RIVER-FLOODS. 101 
 
 the best manner, and their preservation has been guarded since 
 the time of their construction, with all available preservatives 
 against decay. River-embankments, it is true, the Levees of 
 the Mississippi are j but it must be recollected that, until the 
 management of one portion of those works by Col. Alcorn, very 
 little care whatever had been taken in their construction, and 
 equally little in their preservation. The maintenance tax then 
 must continue a heavy burden for some time to come on pro- 
 perty-holders within the Levee j and this tax is subject to 
 reduction in only the amount of care expended in constructing 
 new Levees and in preserving both new and old. The method 
 of construction and the means of protection after construction 
 recommended above, are thus seen to be means adapted 
 to reduction of taxation for Levee purposes on the parties 
 chargeable with their maintenance. In this point of view then 
 it is hoped the popular judgment will hesitate before it under- 
 takes to sneer away recommendations so influential for public 
 good as mere " College " nonsense. These remarks are intended 
 not for the intelligence of the valley ; but for the guidance of that 
 popular mind which may stand at the ballot-box, an impassable 
 obstacle to even such a bold and talented reformer of the Levee- 
 system as the distinguished gentleman to who this volume 
 is inscribed. 
 
102 PRINCIPLES AXD PRACTICE OF 
 
 CHAPTER Y. 
 
 HIGH WATER MARK. 
 
 THE municipal line is supposed, under the present law in 
 Mississippi, to make each down-stream County higher than the 
 flood that may inundate the County above it. Boliver is, 
 therefore, assumed to have no concern in the drainage of Coa- 
 homa. Engineering, then, must trim its practice to meet the 
 absurd system of mere County jurisdictions. The wide revi- 
 sion suggested hereafter, for the correction of flood-levels in 
 Levee-surveys, cannot be carried out satisfactorily at present ; 
 and hence does it become necessary to offer a few remarks on 
 flood-levels in connection with the cramped working of the 
 existing Levee-law. Simple as it may appear, the establish- 
 ment of the High "Water Mark along the lines of Levee, is very 
 often a source of difficulty even to the skillful, and of error to 
 the unskillful administrator of Levee Engineering. * And 
 
 * Illustrative of the errors in construction resulting from want of skill in deter- 
 mining High Water Mark, the following extract is made from the Report of 1856, 
 by the then Commissioner of Levees, in Tunica Judge Hardeman: "The pro- 
 file of Mr. Hewson's survey, &c. * * * * On being with him during the survey, 
 and his taking the field notes of the same, it has been clearly indicated to me, that 
 all the Levees heretofore built in the County, except that portion built and repaired 
 the past season are from one to two feet too low, &c. These Levees should claim 
 our first attention and, if possible, be repaired the coming season." Judge Harde- 
 man might have even stated that the profile from which he speaks, showed some 
 stretches of the embankments so much above High Water Mark as 5| feet ; while it 
 
EMBANKING LANDS FROM RIVER-FLOODS. 103 
 
 error, be it recollected, in this particular is the most dangerous 
 that can happen in all the facts affecting the system. In the 
 first place, it requires great caution in accepting testimony, 
 generally more or less hazardous and loose, as conclusive. 
 Checking the flood-levels above and below the point of diffi- 
 culty in such a case, is the only means of passing from such 
 conflicts of authority to fact. Nor in making such a compari- 
 son must it be concluded that the rate of descent of flood-water 
 is always that of uniformity. Across a bend it may be very 
 rapid ; whereas, the line of flow crossed by a dense forest, 
 thicket, or cane-brake, the flood-line, for a greater or less dis- 
 tance up-stream, will be either that of exceptionally slow 
 descent, or of even a dead-level. But further difficulties apply 
 to the acceptance of local evidence as to High Water Mark. 
 In Levees of wide fore-shore, it is a great, sometimes a danger- 
 ous mistake to accept as absolute the High Water Mark cut on 
 a tree on the spot, during the flood of 1844, or 1850, by even 
 that oracle of flood-facts, an " Old Surveyor." The " Old Sur- 
 veyor,' 7 doubtless, may have even made the mark at the exact 
 height of the flood-water, then and there ; but this amounts to 
 simply nothing, when it is recollected that the flood-water at 
 the point in question was the flood-water of an outflow, and that 
 the river-bottom, while having a fall of 7 or 8 inches per mile 
 along its axis, has, across that axis, a fall of 5 or 6 inches per 
 mile. The Old Surveyor, in short, forgot that, there being a 
 fall in the outflow and also in the ground from the River-bank 
 to his flood-mark, the damming back of that outflow would 
 throw up the flood-level proportionally higher. This consider- 
 
 showed other lengths, so much as eighteen inches below High Water Mark. The 
 report made to him on the subject, holds in fact these words : " The old Levee, for 
 27 miles, requires an average additional height of 1-55 feet, to bring it up to the 
 required height of 3 feet above High Water; in some cases, this length of 
 Levee was found to dip below the High Water-level each such dip involving, in 
 flood-time, certain destruction to considerable lengths of the work above and 
 below it." 
 
104 PRINCIPLES AND PRACTICE OF 
 
 ation is highly necessary in ascertaining the trite working High 
 Water Mark. The ready-made Engineering of the first Levees 
 if indeed, it be any thing more intelligent in some places to- 
 day overlooked the fact that the flood-marks across the bot- 
 tom follow the combined slope of ground and outflow ; and in 
 consequence of this extraordinary error, many a mile of Levee 
 has been swept away, many a dollar, in both scrip and cash, 
 wasted. In practical illustration of the difficulties of fixing the 
 High Water Mark a duty for which every man along the Mis- 
 sissippi regards himself perfectly competent it may be 
 observed here, that the High Water Mark taken, on all the local 
 tests, at a point on the upper reach of " Old River," at Port 
 Royal, in Coahoma County, Mississippi, was higher than the 
 High Water Mark taken with like care, at a point half a mile 
 down-stream, by so grave a difference as 4J feet ! Indeed, the 
 evidence available in the case is so loose and uncertain a guide ; 
 and an error in that guidance, involving the destruction of the 
 Levee, it is highly important, in order to proceed under all the 
 available lights with safety and confidence, that the selected 
 levels of High Water Mark be compared one with another, along 
 each whole drainage district ; and, finally, be revised by com- 
 parison with the selected levels corresponding to them on 
 the other side of the river. But this necessity supposes an 
 improved system of Levee-law and Levee-administration. For 
 the future, however, it is highly important that the public 
 attention be directed to the wisdom of recording, as often as 
 possible, along the river, the height of each year's flood. While 
 the memories of parties living along the bank, on both sides, 
 are fresh with marks of the late disastrous flood, a movement 
 just now would be well timed for the commencement of such a 
 system of record from end to end of the inundated shores. 
 Well-ascertained evidence of this sort may be fixed at once, by 
 the leveller; and after comparison and selection of all the facts, 
 he may transfer the revised flood-heights to a series of 
 
EMBANKING LANDS FROM RIVER-FLOODS. 105 
 
 Bench Marks, sunk for the purpose, at intervals, inside the 
 Levee. These Bench Marks should be driven down, firmly, 
 three or four feet into the ground, so as to guard against their 
 being broken or sunk ; and when their levels may have been 
 duly ascertained, that of each in reference to its flood-level 
 should be marked in red chalk or paint on one side, the num- 
 ber of the Bench Mark being marked, likewise, (in order to 
 identify it) on the other side. This use of Bench Mark-stakes 
 is -universal in the Engineering practice on the "Dikes" of 
 Holland ; and like most of the usages established for the con- 
 duct and maintenance of those works, is highly applicable in 
 the case of the Mississippi embankments. 
 
106 PRINCIPLES AND PRACTICE OF 
 
 CHAPTER VI. 
 
 LOCATION. 
 
 The location of a line of Levee is a consideration involving 
 permanence involving economy of construction and economy 
 of maintenance. Large sums of money have been expended in 
 Levees which, in several instances, have within twelve months of 
 tJicir construction fallen into the river. The cause of this has 
 been ignorance or carelessness in determining the location. 
 Private interest, however, is very often a disturbing influence 
 in forcing the location of Levees from the line of safety and 
 economy. A Planter has frequently been known to be so short- 
 sighted as to have urged, and in fact obtained, the location of a 
 Levee around three sides of even a " turnip patch" rather than 
 consent to the necessity to himself as well as to the general 
 publicof locating that Levee in continuance of its proper align- 
 ment directly across that " turnip patch." * The increased cost 
 
 * In the address explanatory of the causes of Levee failure during the late flood 
 of the Mississippi, the Coahoma Commissioner, while putting the scientific conside- 
 rations of the case in good popular terms, caps those considerations by reference to 
 late practical experience ; on pages 17 and 18 he says : " Motion, whether of solids or 
 fluids, naturally follows straight lines ; and all deviations from that law are accom- 
 plished by an expenditure of impulse on the object occasioning that deviation. A 
 sudden turn in a stream concentrates the whole energy of the fluid-motion on the 
 one point, occasioning that sudden turn, hence the danger of all sudden turns in the 
 Levee. In the original locations of the Levee all these laws of motion were violated ; 
 no regard whatever was paid to the alignment; it was made to wind itself around 
 
EMBANKING LANDS FROM RIVER-FLOODS. 107 
 
 of constructing the embankment to meet this gentleman's nar- 
 row-minded views, as compared with the cost of constructing 
 the embankment on its proper alignment, has very often been 
 ten times greater than the whole value of the additional piece 
 of ground he had, by forcing the Levee out of its course, suc- 
 ceeded in enclosing. This, however, is not the only injustice 
 done under such circumstances to the body of the tax-payers ; 
 for in making the Levee on the zig-zag necessary for the gentle- 
 man's purposes, that course is subject to the additional injus- 
 tice of either reconstructing the work on the proper ground 
 when the zig-zag may have fallen into the river, or of flooding 
 the whole back-country when the shock of the high-water cur- 
 rent striking against it directly, bursts its way in a " crevasse" 
 through that zig-zag's up-stream juttings. The location of 
 Levees, then, it may be seen from these remarks, should not be 
 a mere matter of random ; but should be determined thought- 
 fully with a view, in the first place, to the progress of the 
 river whether in " caving" or " making," and with a view in 
 the next place to the obviation of current-shocks. 
 
 In locating a Levee, the first duty is the mapping out care- 
 fully of the bank ; and, as far as may be done, by a careful 
 sketching of the current-set, the " caving," and the "making." 
 In the case of cavirigs and makings, every information as to 
 their commencement, their rate of progress inwards, and their 
 advance doww-strearn, should be obtained carefully from local 
 information and recorded at the proper points upon the map. 
 The cavings and the makings of the bank pass down-stream in 
 a series of waves, period after period ; and, therefore, by ascer- 
 taining the rate of descent, the rate of penetration of a 
 
 every cow-pen or horse-lot, presenting obtuse angles in the work at many critical 
 points ; and that, too, without any increased strength of embankment at those 
 points. At many such places the Levee during the late rise gave way, for the reason, as 
 assigned, it was without strength to resist the current-shock." The most zealous and 
 best informed friend of the Levee-system thus urges! and endorses the importance of 
 proper attention to the question of alignment. 
 
108 PRINCIPLES AND PRACTICE OF 
 
 " cave," or extension of a " make" at the point of its operation, 
 the location of the Levee opposite that point may be made 
 with a full knowledge of the conditions of its permanence. 
 Levees built one year under such, evidently, necessary precau- 
 tions, will not be swept into the river within either a few 
 years or a few months after their construction. In order to 
 illustrate this important point more fully, the method of mak- 
 ing, and indeed of applying, the notes of " caving" and of 
 " making" as recommended here, may be impressed upon the 
 understanding of young Engineers more readily by a speciality. 
 With this view then is given the following instances. The 
 Chief Engineer of the Mississippi, Ouachita and Red River 
 Railroad, having located the Eastern Terminus of that road at 
 a point which failed to satisfy some of the stockholders, Mr. 
 M. Butt Hewson, then directing the affairs of the Arkansas 
 Midland Railroad, was engaged to report upon the question. 
 The general grounds on which the original location had been 
 based having been taken up by that gentleman as the heads of 
 his inquiry, one of those so made the subject of his investiga- 
 tion was the question of an anticipated change of course in the 
 river by a " Cut-off," opposite Games' Landing. Mr. Hewson's 
 report under this head presents the following illustrative 
 remarks applicable to the considerations referred to here as 
 guiding Levee-locations. 
 
 " A long professional experience in the improvement of 
 rivers, a somewhat intimate acquaintance with the laws of 
 fluid-motion, and a few years observation as a resident on its 
 banks, of the habits of the Mississippi, fail to place my answer 
 to your fourth question within the limits of exact induction. 
 It is much safer to speculate than to demonstrate on the subject 
 of changes of the Mississippi River. I shall, however, furnish 
 you with the facts bearing on your question ; and thereby 
 enable you to judge for yourself as to the logical justice of my 
 inferences. 
 
EMBANKING LANDS FROM EIVER-FLOODS. 109 
 
 " One general law of the Mississippi River subject like all 
 general laws to special exceptions is very plain, viz : the 
 progress of its cavings, like that of its currents, is down-stream. 
 In that portion of the riverunder consideration, the set of the cur- 
 rent from the Arkansas side struck the Eastern bank, some time 
 ago, opposite the residence of Col. Martin ; whereas, now, the 
 most Northerly thread of that current does not strike the same 
 bank for several hundred yards lower down. So much for the 
 general fact of the progression of the cause of active caving. I 
 will now call your attention to the present stage of this pro- 
 gression in the reach of river under consideration. Eleven 
 hundred yards below Col. Martin's house, the present caving 
 commences ; the Southern limits of this caving is not reached 
 for a further distance of eight thousand one hundred yards 
 still lower. The centre of this existing impact on the bank 
 may, therefore, be deduced as midway between those limits of 
 present caving that is to say, 4000 yards below the Northern 
 limit of that caving. The force of a current, always a mini- 
 mum at its outer limits, reaches its maximum in the middle of 
 those limits. Now, the ' Cut-off' suggested, abuts on the bank 
 at 3700 yards below the Northern edge of present caving ; 
 and, therefore, the centre of impact, the point of greatest 
 effect, having already, in its steady progress down-stream, 
 passed below the site of the assumed ' Cut-off' for a distance 
 of 300 yards, we may reasonably conclude that, so far as the 
 supposition of this * Cut-off' is concerned, the period of maxi- 
 mum expectation of greatest likelihood is irrevocably passed. 
 The beam that sustains the pressure of ten tons must be sup- 
 posed perfectly safe from fracture under a like pressure of 
 nine tons. In consideration of these general facts of the case, 
 the inference is clearly opposed to the supposition of this 
 * Cut-off.' In order to examine the same question from 
 another point of view, I will present an analysis of the evidence 
 as to amount and rate of caving, furnished by gentlemen living 
 
110 PRINCIPLES AXD PRACTICE OF 
 
 on the ground, at the several points along the line of this pro- 
 gressing impact. Dr. Offutt states, that opposite his house (a 
 point above Mr. Daniel's house) the bank has caved 400 yards 
 in 20 years ; but at a less rapid rate for the last ten of these, 
 than for the previous ten ; and for the last four of these latter 
 ten, still more slowly. Mr. Wallace affirms that the bank at 
 the same point, has caved 100 yards for the last 7 years ; and 
 as compared with the gross average of these seven, ' very 
 little 7 for the last 2 years. At this place the bank has 
 caved : 
 
 Within the last 20 years, at the rate per year of 20 yards : 
 Within the last 10 years, at a rate per year of less than 20 yards : 
 Within the last 7 years, at the rate per year of 14| yards : 
 Within the last 2 years, at a rate per year of very little. 
 
 " Here, then, is a constant diminution of the effect a dimi- 
 nution in direct accordance with the passing away of the 
 operating cause. Opposite Mr. Daniel's, (a point above the 
 suggested ' Cut-off) the bank has. on the authority of Dr. Offutt, 
 caved, in twenty years, five hundred yards ; the greater part 
 within the last ten years, while the caving for the last year has 
 been at a lower rate. Mr. Wallace's testimony as to this point, 
 places the cavings at two hundred yards within the last seven 
 years ; but for the last two years, very little. These eviden- 
 ces stand thus : l 
 
 Within the last 20 years, at the rate per year of 25 yards : 
 Within the last 10 years, over 25 yards : 
 Within the last 7 years, 28j yards : 
 Within the last 2 years, much less. 
 
 " In this increase of effect, up to a certain time, and diminu- 
 tion of effect since that time, we obtain further evidence of the 
 Southern movement of the centre of impact. Twenty years 
 ago, it had not reached so low down as Daniel's ; and, conse- 
 quently, did not then produce, at that point, its highest effect ; 
 
EMBANKING LANDS FROM RIVER-FLOODS. Ill 
 
 but as it advanced, its progress is traced in the higher effect 
 of the last ten years ; in the still higher effect of the last seven 
 years ; and, as it passed further South, its continued progress 
 in the diminished effect of the last two years. The point upon 
 which the suggested * Cut-off 7 abuts upon the bank has, accord- 
 ing to Mr. "Wallace, caved one hundred yards within the last 
 seven years ; but for the last three years of these seven, at a 
 lower rate : whereas, on the authority of the same gentleman, 
 the bank, opposite Mr. Wilkerson 7 s, (a point below the suggested 
 4 Cut-off 7 ) having caved three hundred yards within the last 
 20 years, has maintained a higher rate of caving for the last 
 ten. This point opposite Wilkerson 7 s, coincides with the pre- 
 sent centre of impact, as inducted above, from the existing 
 limits of effect upon the bank ; and hence we may infer with 
 logical propriety, that the energy (as evinced in the effects) 
 has been increasing at that point for years ; and being, now, 
 at its highest, must from this, forward, steadily diminish, until it 
 shall have, ultimately, passed altogether away. Below Wilker- 
 son 7 s, the testimony of Messrs. Offutt, Wallace, and Harris, 
 shows an increasing energy in the increasing effect ; and, there- 
 fore, as far as the irregularity of the outline, and the resistance 
 of the soils will admit of a strictly exact result in such a case, 
 demonstrating the present centre of effect to be below the * Cut- 
 off/ leads irresistibly to the inference that the time to speak 
 of the suggested ' Cut-off 7 as within the limits of probability, 
 has passed away. What the maximum impact failed to accom- 
 plish cannot be expected from a minor impact nor is there any 
 irregularity in the general outline of the bank to direct a 
 special current against the debouch of the suggested ' Cut-off; 7 
 that outline, being in general a regular curve, may be held to 
 receive, in the consequent uniformity of its resistance, an effect 
 equally distributed. The rate of caving at the supposed ' Cut- 
 off/ proves that the bank at that point is not inferior in cohe- 
 sive strength, to that at any other point included in the 
 
112 PRINCIPLES AXD PRACTICE OF 
 
 information obtained in the case. Besides, the result suggested 
 must now, if it come at all, come from one side ; . for the East- 
 ern debouch of the ' Cut-off' has a making bank. If, then, the 
 * Cut-off' is to result from its present rate of caving, it will not, 
 unless under some new and special combination of causes, occur 
 for upwards of a century and a half. This supposes the centre 
 of effect constant in its point of application ; but with the cen- 
 tre traveling steadily to the Southward, the accomplishment of 
 such a result must be deferred indefinitely. To sum up these 
 remarks on the suggested ' Cut-off :' if the facts of the case do 
 not positively establish that the ' Cut-off' will not be made, 
 they go far to prove that such a supposition is entirely 
 improbable." 
 
 The Keport still further sketches out the method of reason- 
 ing, from the observed facts of " Making," and " Caving," in 
 the following consideration of the question of increased shoal- 
 ing at Games' Landing : 
 
 " To meet your fourth question broadly, I must consider 
 what other changes, as the supposition of the Cut-off must 
 clearly be rejected, is most likely to take place in the Eiver 
 between Ferguson's Point and Games' Landing. The align- 
 ment of the River above the Railroad Terminus shows, as 
 detailed above, a change of course, in a distance of three and 
 a half-miles, of ninety degrees : in other words, the Mississippi 
 River, curving from a point about three-quarters of a mile 
 above the Railroad Terminus until it fronts the house of Mr. 
 W. C. Campbell-^-a distance of three and a half miles turns 
 fully one-quarter round. To divert the whole volume of the 
 Mississippi River so far from its direct course, implies the ex- 
 penditure by the River of an immense energy on the resist- 
 ance causing this divergence ; and hence may we understand, 
 in a general way, the amount of the force employed in opera- 
 ting on the bank between Mr. Campbell's plantation and the 
 site of the Railroad Terminus. The caving consequent on the 
 
EMBANKING LANDS FROM RIVER-FLOODS. 113 
 
 force so exerted against the bank between those points, stands 
 at present in its progress to the southward, as follows : It 
 begins at a point 500 yards below Mr. Campbell's ; and extend- 
 ing down the River-bank, to the head of Island No. 80, a point 
 1200 yards below the Railroad depot, the centre of impact (the 
 point of greatest effect) being at the present time situated, 
 therefore, upwards of 2700 yards higher up-stream than the 
 Railroad Terminus. The rate of effect at points along this 
 bank I am unable to say ; but the maximum effect having yet 
 to operate over a space of 2700 yards before it shall have 
 reached the Terminus, has yet, in obedience to an infallible law 
 of the River, to come sweeping down with all its powers of 
 change and destruction on what remains of Ferguson's Point. 
 In the march down-stream of the axis of current lies the cause 
 of any such change of channel as may be looked for between 
 the Railroad Terminus and Games' Landing. When the cur- 
 rent of the River first swept the Northern bank of Ferguson's 
 Point, the Southern bank of that point lay at the head of a line 
 of slack-water. Island 80 resulted from this ; for the matter 
 that passes off in suspension under the impulse of a current of 
 4 or 5 miles an hour, will be precipitated in currents of one 
 or two miles an hour. Now, however, Ferguson's Point has 
 been to a considerable extent carried away, within the last six 
 years, to an extent, according to Col. B. Gaines and Mr. 
 Reinhart, of eighty yards ; and as a consequence, the Island 
 formed under the shelter of that Point begins now to receive 
 the shock of the river current." Observations and applica- 
 tions of the above description being employed as a guide in 
 the case of the location of Levees, the determination of 
 those locations may be made with a proper regard to the most 
 important considerations affecting their permanence. All 
 points of the bank being thus examined under the light of the 
 circumstances affecting their permanence, the limits of per- 
 manence inferred therefrom, must be noted at intervals on the 
 
114 PRINCIPLES AND PRACTICE OF 
 
 plan ; and the alignment of the Levee being made to conform to 
 the considerations proper to itself, the location must be laid 
 down on the plan within the restrictions of these limits of 
 permanence. The laws governing the alignment of water- 
 embankments, like those governing the alignment of Railroad 
 tracks, point in the first instance to straight lines. The course 
 of motion, whether of solids or fluids, is naturally rectilineal. 
 As has been observed in the latter of the two foregoing ex- 
 tracts from the report of Mr. Hewson, the diversion of motion 
 from its original line to any other line, involves the expendi- 
 ture of more or less mechanical effect. In diverting a surface 
 layer of the Mississippi flood-water that mass moving at the 
 rate of some 6 miles an hour from one course to another, it 
 can be readily understood that the expenditure of mechanical 
 effect is very great. In order, then, to discharge this unavoid- 
 able force with the least possible danger to the Levee, it should 
 (so that it be distributed equally over a large space) be dis- 
 charged invariably over a curve. These few simple principles 
 point out clearly the rules governing Levee alignment 
 straight lines where such are practicable, and regular curves 
 where they are not. Laying down this curvilinear rectilinear 
 alignment in a manner as far as possible to accord with the 
 general lines of the river-currents, the Levee will be exposed 
 at all its points to the least possible shocks and washes. The 
 limits of permanence laid down on the plan according to the 
 considerations premised above, the lines of current controling 
 the general direction of the alignment, that alignment making 
 all its changes of direction over regular curves may be laid 
 down finally on the plan with the fullest faith in it as the loca- 
 tion of greatest safety and greatest economy. Often, however, 
 it will occur in reasoning on the considerations guiding in lay- 
 ing down the Levee-route on the plan, that two or more routes 
 may appear to possess equal merits. Laying down all these 
 routes on the map, each must be made a subject of instrumen- 
 
EMBANKING LANDS FROM RIVER-FLOODS. 115 
 
 tation and estimation ; and always taking into consideration 
 that the closer the alignment adheres to the limits of perma- 
 nence the greater the amount of good to the public, the relative 
 cost of the respective routes determining, finally, as to the one 
 for adoption. So much then for the general considerations 
 affecting location. Special considerations in reference to 
 stretches of considerably heavy embankment, may apply 
 such, for instance, as ridges furnishing, within the limits of 
 permanence, an economical location for the Leveeing of a neck 
 of swamp. These must in all such cases be examined carefully 
 first by the reconnoisance of a professional eye, and next, if 
 found necessary, by instrumentation and estimation. So much 
 then for the considerations applicable to location under the 
 cramped action of the Mississippi Levee-laws. 
 
116 PRINCIPLES AND PRACTICE OP 
 
 CHAPTER VII. 
 
 SURVEYS . 
 
 HIGH Water Mark, it has been shown, cannot be obtained so 
 readily as is supposed by the populace. On the contrary, the 
 correct determination of the flood-line for fixing the height of 
 a Levee, is a duty that involves, not only sound judgment and 
 patient investigation ; but also careful and extensive instru- 
 mentation. The location of a Levee, it has also been pointed 
 out, is something more than a matter of off-hand expediency. 
 This duty of the Levee-system is at present like the determi- 
 nation of the flood-line assumed popularly to be fully within 
 the knowledge and capacity of every man living on the banks 
 of the river. The considerations affecting the discharge of 
 such a task have, however, been shown already to be too in- 
 tricate, too extensive, too delicate, to be grouped and combined 
 into correct results by even men of fair standing amongst the 
 members of the profession as Field Engineers. Location, with 
 the commonest pretensions to care and science, requires, as has 
 been indicated in the remarks on that head, as a first necessity, 
 a full careful survey, an exact and special map. The first duty 
 then of an improved system of Leveeing should be the prepar- 
 ation of maps and profiles the surveys for those maps and 
 profiles to be extended from end to end of those sections of 
 country referred to hereafter as Drainage Districts. These 
 surveys can be directed only by a mind quick in observation 
 
EMBANKING LANDS FROM RIVER-FLOODS. 117 
 
 and ingenious in inference this quickness and ingenuity guided 
 by a familiarity with fluid-motion and river phenomena. They 
 should show by actual offset-chaining the line of bank ; and by 
 careful sketching, all " makes," " bars," and currents. These 
 instrumentations should bring out all the facts of cavings, so 
 as to furnish to the mapper the penetration, progress, and 
 stage of each cave. All facts of possible or probable influence 
 on the objects of the survey such for instance as the facts of 
 Moon Lake in Mississippi, of Old Town Lake in Arkansas, of 
 Bayou Atchafalya in Louisiana, their position, form, level, 
 flow, &c. &c ought to be carefully ascertained and connected 
 with the great body of the facts of the District survey. Every 
 foot of survey, whether of experimental lines along ridges, 
 across swamps, or any where else, within a Drainage District, 
 should be laid down regularly when completed and connected 
 with the general survey on the plans and profiles of that Dis- 
 trict. These plans should consist of two sets ; one set on a 
 scale as large as practicable for a map of convenient size, 
 showing the ground along the whole front of its whole District. 
 Divided into squares by light lines across its face, this map 
 should be made an index map by numbers set on each square 
 so shown, to the several sheets of the second set of maps a 
 set made to a sufficiently large scale to embody all the minutiae 
 necessary for practical purposes. These enlarged working- 
 plans, amongst the other particulars referred to as guides in 
 location, should show the site and title of all survey-stations, 
 the site and number of all Bench Marks, the elevations of the 
 Bench Marks recorded duly by transfer from the District pro- 
 file. The first exact and minute survey of a Drainage District 
 effected by a special staff, the constant staff required for the 
 Engineering direction of the District-works, should spend all the 
 spare time from construction-duties, in keeping up, by survey, 
 connected records, on the working plans, of all changes of " bars," 
 increases of " makes," shiftingsof currents, penetrations and pro- 
 
118 PRINCIPLES AND PRACTICE OP 
 
 gressions of " caves." These facts ascertained and laid down 
 on the plans, year after year, the continuity of the records on 
 the whole river will, after a time, enable a Levee-administration 
 to reduce to something like scientific exactness, every consid- 
 eration affecting the perfect practical efficiency of their most 
 important duties. 
 
 The maps described here have been deduced as necessities 
 of location from the circumstances affecting it on but one side 
 of the river. But it has already been shadowed out in the 
 remark on that subject, that the location of a work on either 
 side cannot be made with complete care without the exact com- 
 parison with the location on the side opposite. The practical 
 difficulties referred to, under the head of High Water Mark, 
 also suggest the comparison of levels on one side of the river, 
 with levels on the other side. But the necessity arising from 
 these considerations is indicated still more forcibly from 
 another point of view. The remarks offered on location show 
 the necessity of avoiding all causes of excessive pressures, or 
 shocks upon river-embankments. The currents treated with 
 disregard, and the lines of least resistance duly observed, in 
 location of a Levee, the conditions of location in reference to 
 yhocks are fully met, so far as the considerations affecting them 
 on that particular side of the river. But let it be assumed that 
 the Levees up-stream have, on both sides of the river, a consid- 
 erable breadth of fore-shore ; while at the point of this locally 
 judicious location, the Levee on both sides happen to have for 
 their fore-shore, each but a narrow strip. The width from 
 Levee to Levee, across the river, may thus happen, up-stream, 
 to be large, while below at the point of the locally good loca- 
 tion the width across the river from Levee to Levee may 
 happen to be comparatively narrow. This sudden contraction 
 of the flood-flow will throw an increased shock of current on 
 the Levees at the point of that contraction j and thus does 
 the location of a Levee on one side, without due regard to that 
 
EMBANKING LANDS FROM EIVER-FLOODS. 119 
 
 of the Levee on the other side, involve some of those avoidable 
 contingencies of breaching the embankments which judicious 
 location undertakes to guard against. Proper location, then, 
 notwithstanding conformity with all considerations of " cave,' ; 
 current, and alignment, on one side of the river, cannot be made 
 without comparing the location based on all these, with the 
 location on the other side. The narrowest width of the river- 
 flow, in the natural state, is said, in the late able pamphlet of 
 Col. Alcorn, to be opposite Randolph, in Tennessee. A bluff 
 at one side and a high bank on the other side, it appears that 
 at that place the floods of the Mississippi pass off, without any 
 particular increase of current, or wear of the bank, within a 
 width of 2,000 yards. A proper survey of the river might, pro- 
 bably throw further and more correct light on this particular 
 fact ; but whether Randolph be, or be not the site, and, 
 whether 2,000 yards be, or be not the width, of the narrowest 
 natural channel of flood-water, some site and some width 
 answering those conditions ought to be ascertained for fixing the 
 ruling width of water-way between the lines of river-embank- 
 ment. This ruling width determined in reference to the 
 width, section, and current of several "narrows" in the flood- 
 flow, the proper location of Levees on either side of the river, 
 requiring that the flood-width be never lower than the stand- 
 ard, such a location on one side can be made only pari-passu with 
 the corresponding location on the other side. An inter-littoral 
 survey is seen thus to be a necessity of economic and perma- 
 nent location. This survey connecting District surveys across 
 the river, does not require absolutely to be one of detail. In- 
 termediate Islands should certainly be embraced in it ; but in 
 consideration of the cost of such an extension of labor, it is, 
 perhaps, better (for some time at least) to omit soundings. A 
 skeleton Trigonometrical survey, then, connecting stations in 
 local surveys on both shores, and on intervening islands, is all 
 that is absolutely necessary in addition to the surveys already 
 
120 PRINCIPLES AND PRACTICE OP 
 
 described for completing the enquiries and records necessary 
 to a perfectly correct and economic system of Levee-adminis- 
 tration. The triangulation necessary for this survey, should 
 be carried out with a view to fixing each station under the 
 endorsement of one or more checks j but due regard to be 
 paid, in all cases, to the regularity of the shape of the triangles, 
 and to the including in each station-book on the field, of each 
 of the stations that may be possibly combined in any one 
 triangle. The correction of bases, the adjustment, in estima- 
 tion, of spherical excess, &c., are details that, in addition to all 
 the care suggested for the field, are highly necessary in carry- 
 ing a base line of some 2000 or 3000 yards, with all the correc- 
 tions of even several intermediate checks, through a series of 
 some eight or ten hundred triangles. The triangulation, 
 however, " poled out," the angles taken, the base measured, 
 and the calculations made, the District-surveys may be carried 
 out in detail as described, connecting regularly with the 
 stations of the triangulation. The diagram of the trigonomet- 
 rical points having been laid down, the filling in of this 
 diagram, on each side, with the details of each local survey, 
 will not only guarantee an accuracy otherwise unobtainable in that 
 local survey, but will also present a perfect connection of the 
 facts on both sides of the river. This connecting survey will, 
 in the first place, by doubling the data, lead to reliable infer- 
 ences in all cases as to the height of High Water Mark will, 
 by embracing in exact detail the facts of all the " narrows," 
 limiting the width of flood-flow, lead to correct deductions as 
 to the " ruling" width proper in the case of opposite Levees ; 
 and by representing the relative position of Levee-alignment 
 on each side of the stream, point to those modifications or 
 changes of site that may be necessary for conformity with the 
 conditions of efficiency and permanence. 
 
EMBANKING LANDS FROM RIVER-FLOODS. 121 
 
 CHAPTER VIII. 
 
 The subjects of flood-line, location and survey involve neces- 
 sities at evident conflict with the present system of Levee- 
 legislation. In Arkansas and in Louisiana the administration 
 of the drainage-interests are in the charge of the State ; in Mis- 
 sissippi, in Tennessee, and in Missouri, the charge of those 
 interests is parcelled out among the Biver-counties. In all these 
 
 * The opinions put forth here are found to be strikingly coincident with those 
 of the Chief Commissioner of the Levees of Mississippi. His Report for 1856, to 
 the Legislature of that State, has just been brought under the notice of 
 the writer of this, and presents an opportunity for tho endorsement of the views 
 given under the above head, as in the following extract from that Report by so well- 
 informed and judicious an observer : 
 
 "The practical results of the law placing the direction of the Levee within the 
 respective limits of each County on tho river, in the hands of a Board constituted on 
 the principle of local representation, have been, so far as those results have fallen 
 under my observation, decidedly unfavorable to the law. The act substituting a sin- 
 gle Commissioner for these Boards of Commissioners in Tunica and Coahoma, 
 has worked, in my opinion, much more advantageously to the interests of the 
 Levee. 
 
 " This individual management is, in truth, in more close conformity with the phy- 
 sical principle that should direct legislation in this great practical work. No mere 
 municipal line can divide an interest which is declared one and indivisible by the 
 eternal law that rolls out the floods of the Mississippi in an unbroken whole. In 
 not only principle, but also in practice, do I find reason to recommend this system 
 of individual control in the design and construction of our Levee. It went into 
 operation in the County of Coahoma two years ago, receiving from the previous re- 
 
122 PRINCIPLES AND PEACTICE OP 
 
 cases the legislation is injudicious in its working in Arkansas 
 and Louisiana less so, however, than in Tennessee, Missouri, and 
 Mississippi. The latter States presenting the extreme form of 
 objection to non-conformity of Levee-law with Levee-require- 
 ment, the following remarks on points of this non-conformity are 
 confined to the legislation of those States. The experience that 
 has lead to the preparation of these remarks, has been acquired 
 in Arkansas, and in Mississippi ; and as the latter is one of the 
 
 gime, the legacy of a wasted resource, an exhausted treasury, an unsettled indebt- 
 edness, an imperfect record, an insufficient and incomplete Levee, and last, but 
 worst of all, an almost total wreck of public confidence in any municipal adminis- 
 tration. But what now, in two short years, is the condition of those affairs 7 Though 
 I discuss a principle only in this case, it is not for me to answer, nor is my answer 
 necessary when the answer has been already given in general terms by the County. 
 This principle of individual management in carrying out our Levee has, in a direct 
 issue with the principle of divided management, been endorsed emphatically by the 
 intelligent people of Coahoma. Aware that the unity of the Levee could not be 
 broken by municipal divisions, I had the honor to bring forward, two years ago, the 
 existing law, giving a general jurisdiction over the Levee to the ' Superior Board of 
 Levee Commissioners.' The working results of this law have fallen short of the 
 physical principle which was sought to be reached by it. The interest of the river 
 Counties is in truth such a perfect unit in reference to the Levee, more or less diffi- 
 culty will always be found in carrying out so absolute a unity, under even the 
 strongest organization of independent jurisdiction. A breach in the Levee at the 
 upper end of Issaquena County, would, in the event of overflow through that breach, 
 cause the destruction of property in the County of Washington by back-water. An 
 overflow through the Levee at the lower line of Bolivar County, while it may do very lit- 
 tle damage in Bolivar, may spread out one great sheet over the length and breadth of 
 Washington County. In Tunica, an active caving of the river bank has already ad- 
 vanced within some fifty yards of the Levee, and still advancing, the next flood in 
 the Mississippi will, in all probability, break in an immense volume into Eagle Lake. 
 Now, to the greater portion of the people of Tunica, this result is a matter of com- 
 parative indifference whereas the outfall from Eagle Lake, being Southwardly and 
 Westwardly, such a result will spread devastation far and wide in Coahoma ; so the 
 construction of the Levee in the Southern border of De Soto, is a matter to the peo- 
 ple of that County of comparative indifference the majority interest is already pro- 
 vided for the Levee is left open, and the country South of them becomes the suf- 
 ferer. The local administration is the supreme power over that portion of the river 
 

 EMBANKING LANDS FROM EIVER-FLOODS. 123 
 
 States whose Levee-legislation illustrates its conflict with 
 Levee-expediences most forcibly, it is therefore selected here 
 to illustrate that fact by examples mainly special to itself. The 
 conclusions, however, though drawn to some extent for special 
 instances, are general in their application to those States where 
 Levee-administration is distended to the extent of a whole 
 State, and also to those where it is narrowed* down to the limits 
 of a County. 
 
 Drainage-legislation is based on error in limiting the admin- 
 
 within the limits of De Soto. Tunica has not the protection of a representation of 
 the common interest which is bound up in the Levee an indivisible unit. Again, 
 the Leveeing of those heads of Sunflower which traverse Lewis' Swamp, in tho 
 County of Coahoma, is a work of secondary concern to the great majority of the peo- 
 ple of that County, but though situated within a jurisdiction regarding it with com- 
 parative indifference, this part of the Levee is of much deeper importance to the 
 upper portion of Bolivar, than any like distance of low bank on her own front. 
 While Coahoma required outlays at other points of much more urgency to her safe- 
 ty, her resources have naturally been employed at those points to the consequent 
 injury of an immense amount of property in a neighboring jurisdiction. 
 
 " Indeed, such has been the interest felt in Bolivar in regard to this Levee, that 
 influential citizens of that County, had offered, in addition to the only resources 
 which Coahoma could agree to apply to that purpose, to pay a large bonus to any 
 contractors, who would bind themselves in a contract with Coahoma, to Leveo 
 Lewis' Swamp. But, if a flood shall have risen before this swamp is Leveed, under 
 the present state of affairs, how bitterly will the people of Bolivar regret, that while 
 the local interests in tho Levee have been provided for by an authority and an ad- 
 ministration, there is no head, no strong individuality of general management, to 
 represent the strong individuality of general interest. Wise legislation on practical 
 improvements must always conform to physical laws. A general controlling authority 
 is necessary also in this point of view, to represent the great and wide considerations 
 involved in the intelligent design, and the straightforward independence, required 
 in the faithful execution of that design, from end to end of that great physical unit, 
 the Levee of the Mississippi and Yazoo bottom. From the commencement of the 
 system, I have sought to convince the Levee interest of the necessity of this individ- 
 uality ; thus far my efforts have been unavailing. The plan of operation is one that 
 I have never approved. I have been driven to its support for the reason, that no 
 other plan could be suggested which could command the united support of the in- 
 terests involved." 
 
124 PRINCIPLES AND PEACTICE OF 
 
 istration under it by arbitrary lines. In Shelby County, Ten- 
 nessee, the proper administration of the Levees is not placed 
 under the guarantee of any considerable interest. Some eight 
 or ten thousand acres of swamp subject to the overflows of 
 Nonconnah Creek and Horn Lake must always constitute an 
 insufficient interest for the enforcement . of an independent 
 administrator of the Drainage-works of that area in the con- 
 struction, protection, and maintenance of the Levees under his 
 control Levees extending to a length of some 15 miles. In- 
 deed a question presents itself this moment as to whether, 
 within the section referred to, there exists a single plantation, 
 there resides permanently even a solitary squatter. The fact 
 is, the Leveeing of the tract in question cannot, in all likeli- 
 hood, be said under existing legislation to be the business of 
 any one ; but even if it be the business of any one, the area to 
 be enclosed does not present, in all probability, the ways and 
 means for raising does not in short present a sufficient induce- 
 ment to justify the considerable expenditure required for its 
 embankment a sum that cannot be less than some $30,000. 
 And yet, if this part of the bottom be left unenclosed, the whole 
 Levee from the Tennessee line to the Yazoo, can be saved from 
 utter uselessness for the drainage of the Valley but by a special 
 work pressing on the limited resources of the Levee-interesis in 
 De Soto ! If a physical facility have not brought this special em- 
 bankment within the limits of the ability of De Soto, the inun- 
 dations from Horn Lake will ignore the hamperings of Ten- 
 nessee and Mississippi legislation by forcing combined action of 
 all the counties between the Nonconnah and the Yazoo, in the 
 construction, protection, and maintenance, of either a general 
 Levee from the Tennessee line to the Nonconnah hills, or of a 
 special embankment in De Soto County from the existing 
 River-Levee to the Coldwater high lands. But instances of the 
 bad adaptation of the present law are numerous. In Tunica 
 County, Mississippi, the Commissioner is charged with several 
 
EMBANKING LANDS FROM RIVER-FLOODS. 125 
 
 Keys of the drainage of Coahoma, Sunflower, Tallahatchee that 
 at Buck Island Bayou, that at Couple-Timber Bayou &c. These, 
 however, it may be said are Keys also to the Drainage of 
 Tunica itself ; and, therefore, are their safe-keeping placed in 
 the hands of the local Commissioners under some guarantee. 
 Tunica, however, is charged with another Key to the Drainage 
 of Coahoma, Sunflower, and Tallahatchee the Levee immedi- 
 ately covering the plantations on the North shore of Moon Lake. 
 This latter Levee protects little or none of the settlements in 
 Tunica ; whereas the flood-water rushing through a crevasse 
 therein sweeping southwardly across Moon Lake and the Yazoo, 
 will inundate the fields and homesteads of Tallahatchee, Sun- 
 flower, and Coahoma. Want of interest in its construction, want 
 of funds to pay for that construction, demands on their treasury 
 and attention at points of concern to themselves, may lead the 
 people of Tunica at any moment to regard this Key to the 
 Drainage of Coahoma and its adjoining counties, with a very 
 natural, and indeed quite excusable neglect. The most vital 
 interests, then, of Coahoma, Sunflower, and Tallahatchee, are 
 placed, by the system of County-jurisdiction in Leveeing, 
 beyond the control of these counties placed in the hands of parties 
 who can afford without loss, to regard the protection of those 
 interests with indifference. A tax to be collected from them- 
 selves for the construction or repair of the Levee covering Moon . 
 Lake protecting Coahoma would, naturally enough, be not 
 carried probably without some effort amongst the people of 
 Tunica. But the lower Counties show the working of the 
 system of local-jurisdiction in still more objectionable lights. 
 In Coahoma County there may be said to be no settlement 
 south of Lewis' Swamp. The Coahoma people, as a body, care 
 very little therefore, about the Leveeing of Lewis 7 Swamp ; 
 whereas, the floods breaking through that swamp, may at any 
 time after the failure of its Levee, inundate at even ordinary 
 floods, the lands and homes of Bolivar and Sunflower, unless 
 
126 PRINCIPLES AND PEACTICE OP 
 
 Levee-jurisdiction be regulated by some limits more practical 
 in their operation than those of arbitrary lines. The hampered 
 workings of Levee-legislation are thus seen by a few illustra- 
 tions to be unjust and unsafe for the whole Valley of the Yazoo 
 for De Soto, for Tunica, for Coahoma, for Bolivar, for Sunflower, 
 for Tallahatchee, and (the contingencies of local indifference, 
 local urgencies, and local taxation, accumulating unfavorably as 
 the testing of this legislation is carried down-stream) the injus- 
 tice and unsafety is still greater in Washington than in Bolivar ; 
 and as compared with Washington is still greater in Issaquena. 
 But what is the remedy for the evils of the present system 
 of Levee-government? An extension of Levee-jurisdiction 
 according to certain physical proprieties. Working necessities 
 point clearly to the removal of the existing limits on the ad- 
 ministration, in the State of Mississippi, of river embank- 
 ments. The location considerations referred to above, operate 
 in full force, whether or not the ground lie one-half in Wash- 
 ington, the other half in Issaquena. In locations so circum- 
 stanced the surveys to be made must be common to both counties. 
 The flood-level too, is a subject of inquiry that, as shown above, 
 cannot be cut short by a mere legislative fiction ; and, here, 
 again, is another point in which the practical duties of Levee- 
 administration ignore the system of imaginary limits to Levee- 
 jurisdiction. Other considerations point still more forcibly to 
 the necessity of seeking some new boundaries for the limita- 
 tions proper to that jurisdiction. Bolivar's voice and Sunflow- 
 er's voice in the appointment of the Commissioner directing 
 the Levees of Coahoma, will guarantee the construction, 
 protection, and maintenance, of a Levee across Lewis' Swamp, 
 quite as soon and quite as surely, as that across the Yazoo 
 Pass, or at any other point in Coahoma. So also as between 
 Coahoma and Tunica : * give Coahoma, Tallahatchee, Sun- 
 
 * The joint interest of conterminous counties in the proper administration of 
 their respective Levees and in the making and skill of their respective surveys, is 
 
EMBANKING LANDS FROM RIVER-FLOODS. 127 
 
 flower, voles in the election of the administrator of Levees in 
 Tunica ; and Coahoma, Tallahatchee, Sunflower, will assuredly 
 be thereafter saved from the dangers, the, perhaps, ruinous in- 
 difference that, under the present law, may at any moment 
 inundate their hearths and fields by overflows discharged upon 
 them in desolating volumes through Moon Lake. But what 
 distribution of jurisdiction will conform best to the practical 
 and social considerations entering into Levee-administration ? 
 From Cape Girardeau in Missouri, where the highlands abut 
 upon the river, to the mouth of the St. Francis in Arkansas, 
 where the back-drainage of the intervening country must be 
 discharged, defines a Levee-district, which, bound together by 
 a community of interest, is for all the purposes of proper 
 Levee-administration, an absolute unity. From Sterling in 
 Arkansas, at the mouth of the St. Francis, where the Levee 
 rests on the slopes of Crowley's Ridge, to the mouth of White 
 River, where the back-drainage of the intervening country 
 discharges, is also, so far as the Mississippi Levees are concern- 
 ed, a unit in Levee-interest ; and, therefore, should be a unit 
 
 pointed out by inference in the following remarks of Judge Hardeman, as Levee- 
 Commissioner to Tunica County : " The object of making this survey was, with 
 the then indication of the active caving of the bank of the Kiver at the Southern 
 part of Trotter's Field, to ascertain whether for the protection of the back-country, 
 we would be compelled to Levee around Eagle Lake. * * * The indication of cave, 
 &c., which may save this county and Cbahoma a considerable amount of money, &c. 
 The question, however, as to whether we go around Eagle Lake ought to be deter- 
 mined by concert of action between the Levee Commissioners of Tunica and 
 Coahoma, as they may decide as to the best interests of the two counties ; for, as 
 before remarked, there is a common interest of the two counties in erecting a 
 Levee across the Pass, &c." Report for 1856, page 5. This extract specifies an 
 instance in which the location of a Levee in one Levee-jurisdiction is held to involve 
 a loss or a gain of a " considerable amount" of money to the tax-payers of another 
 Levee-jurisdiction ; and specifies also an instance in which the construction of a 
 Levee within one jurisdiction is considered to be a question of drainage within 
 another jurisdiction. And the parties thus concerned, in the one case in their 
 pockets and in the other case in their property, to be deprived of all influence in 
 making that location, or in expediting that construction. 
 
128 PRINCIPLES AND PRACTICE OF 
 
 in Levee- administration. From Pine Bluff, the nearest escarp- 
 ment to the Mississippi of the Arkansas Uplands, to the mouth 
 of Red River in Louisiana the outlet of the rain-shed of the 
 intervening bottom lands the community of interest in the 
 inclosing Levee is so indissoluble that the proper administration 
 of that Levee over-riding all imaginary boundaries whether 
 of County or of State must, in furtherance of sound policy 
 and capable management, be centered of necessity in one and 
 the same intelligence. On the Eastern bank it has already 
 been indicated sufficiently plainly, that the Levee-interests from 
 the base of the hills below Memphis in Tennessee to the mouth 
 of the Yazoo River the debouch-channel of the back-drainage 
 of the included area is so thoroughly identical in its drainage 
 affairs socially and practically that the administration of 
 those affairs within that area has been described by Col. Alcorn, 
 most correctly, as " one and indivisible." The natural the 
 social and the working definitions of the remaining jurisdid- 
 tions in Louisiana and in Mississippi, may, with the views 
 presented above, be determined by those acquainted with 
 the physics of those sections ; and so also of the jurisdic- 
 tions in Tennessee, Missouri and Illinois. The limits as- 
 signed the districts defined here are, it ought to be 
 observed, those on their Mississippi front, the limits on 
 their inland side, in each case being located as hereafter 
 indicated on such lines as may be necessary for the equal dis- 
 tribution of Levee taxation. Sufficient, however, has been 
 said here to show that physical considerations applied socially 
 and practically, while ignoring the existing limits to Levee-ad- 
 ministration, describe plainly certain limits demanded for its 
 efficiency. * 
 
 * Some four years ago the grounds taken here were taken by Col. Alcorn, see note 
 to page 121, in urging the consolidation of Levee-government in his Report as 
 chairman of the Superior Board of Levee- Commissioners, to the then Legislature of 
 Mississippi. Tho essential unity of Levee-management was suggested subsequently 
 
EMBANKING LANDS FROM RIVER-FLOODS. 129 
 
 Unity of interest can be served truly by only administrative 
 unity. Each Drainage District then (as the united areas referred 
 to above may be termed,) ought to be placed under a single 
 administrator. One Commissioner should be charged with 
 the direction of drainage embankments from Cape Girardeau 
 to the mouth of the St. Francis ; one from the mouth of the St. 
 Francis to that of Arkansas River ; another from Pine Bluff to 
 the mouth of Red River. On the opposite side a single Commis- 
 sioner should be charged with the control of the Levee-interests 
 from the Nonconnah to the debouch of the Yazoo. But while 
 the social and the practical considerations in the case conspire 
 
 by Judge Hardeman, Levee-Commissioner of Tunica in his report for 1856, to his fellow 
 commissioners, Messrs. E. B. Bridges and J. A. Cole, in the following judicious re- 
 marks : " The propriety of this repeal may be a question of doubtful policy, as it 
 must be apparent to you that a common interest in the Levees fronting all the counties 
 on the Mississippi Eiver from Horn Lake to the mouth of Yazoo River ought to be ap- 
 preciated by all land-holders within that Delta formed by Coldwater, Tallahatchee, 
 and Yazoo Rivers, to its entrance with the Mississippi, a distance of 350 miles, em- 
 bracing a part of the County of De Soto, all of Tunica, Coahoma, Bolivar, Washing- 
 ton, Issaquena, Sunflower, and part of the counties of Warren, Yazoo, Tallahatchee, 
 and Pauola, * * * Tunica County tax-payers on lands bordering on Cold- 
 water, are as much interested in the Leveeing around Horn Lake, De Soto County, 
 as they are in the Levee of their own County fronting the Mississippi River ; also 
 the land-owners bordering on the Mississippi River and Coldwater are equally inter- 
 ested in Leveeing the Yazoo Pass in Coahoma, as the water in making its way 
 through the Pass backs up through Moon Lake, &c., to the town of Austin and its vicin- 
 ity. The question may be well asked : can this common interest in the Levees on the river 
 be carried on without concert of action, $c." Messrs. Hardeman, Bridges, and Cole, are 
 gentlemen of intelligence, of practical acquaintance with the working of the Levee 
 system ; and, as such, their testimony to the fact of Levee-unity, so far as it goes, is 
 highly valuable. The remarks in the above extract point to the restoration of the 
 Superior Board of Commissioners as fulfilling all the suggestions of Levee-concert ; 
 but, loose and scattered in its parts, the action of that Board lias already been found 
 to be utterly inefficient. Some other form of government, therefore, must be in- 
 stituted to meet the universally accepted fact of Levee-unity ; and the form of a gen- 
 eral Board having been tried and found wanting, the necessities of the moment 
 point to the only practical indeed the only untried form remaining, that of admin- 
 i strati ve individuality. 
 
130 PRINCIPLES AND PRACTICE OP 
 
 to define the working limits of District Levee-jurisdictions, the 
 practical considerations point to a conclusion still in advance of 
 existing systems. The working expediences involved in capable 
 administration of Levee-drainage are not confined to one side of 
 the Mississippi. The comparison of High Water data obtainable 
 on the East bank with that obtainable on the West bank, has 
 been referred to as an expediency in determining the question 
 of High Water Mark. This comparison, then, indicates the ex- 
 tension of District-administration to an administration of wider 
 scope and more general duties. The necessity of full know- 
 ledge of the location-facts on the opposite side, and of certain 
 accord between the locations on both sides, is another instance 
 under a system of District-management of a commingling that 
 leads plainly to a further widening of administrative commu- 
 nity. A fusion of District units is an expediency on these 
 grounds ; and therefore, on the further ground that, only by 
 such a fusion can the Levee-interest of the great Valley of the 
 Mississippi receive the first great contribution, the prime 
 essential, of a broad, capable administration a full, correct and 
 connected set of working maps. The scientific and practical 
 conditions of the drainage of the Yalley by Levees require, 
 therefore, that the administration of each Drainage District to 
 the full extent of its natural limits, be placed in the hands of 
 an individual Commissioner ; and further require that the admin- 
 istration of all joint-duties of the Drainage Districts on both 
 sides of the river, be placed in the hands of those individual 
 Commissioners assembled in general Board or Council. Legis- 
 lation based on the system of administration sketched out 
 here, is clearly the only one adapted to the direction of those 
 important works under the lights of scientific principle, of 
 practical forethought, of sound economy. 
 
 Great difficulties, however, obstruct the effective working 
 of proper machinery for the management of Mississippi Levees. 
 The popular intelligence holding the purse-strings of the system 
 
EMBANKING LANDS FROM RIVER-FLOODS. 131 
 
 does not, in some cases, go to the extent of recognizing in 
 Leveeing, any skill beyond that of its own crude observation. 
 It sometimes commits the mistake of ignoring the existence of 
 centres of special knowledge, whether in Medicine or in Engi- 
 neering. Col. Alcorn has been constantly hampered in his 
 Commission by this condition of public opinion. " Such," he 
 says, in his last pamphlet, " is the disposition to economise, 
 that complaints are made should the Commissioner employ an 
 Engineer at a salary of fifteen hundred a year ! The subject 
 must be elevated above this, or decent men will cease to be 
 connected with it." Laughable as such difficulties to proper 
 administration as those indicated in this extract may appear, 
 they present in practice serious embarrassment to intelligent 
 and vigorous administration.* His intelligence, his personal 
 
 * One of the embarrassments to the Levee-reformer, remaining as a consequence 
 of the former employment of non-professional men for Engineering Levees, presents 
 itself in the want of faith amongst even intelligent Planters of the Valley, in the 
 skill and independence of the professional Engineer. Identified widely and favor- 
 ably, as has been the name of Mr. M. Butt Hewson, with the leading measures of 
 public improvement in the South- West, for several years known, as it is, honorably 
 to the professional Engineer, and the Railroad public generally, from New York to 
 New Orleans the Chairman of the Board of Levee-Commissioners for the State of 
 Mississippi, was obliged, in 1855, to go into the defence hinted at in the following 
 remarks from his Report of that year: "The Messrs. Hewson, both M. Butt, the 
 elder, and William, the younger, are Civil Engineers by profession have been 
 schooled to the science have, by competent men, been heretofore employed 
 directing some of the most important public works of the South. Their labors have 
 passed the ordeal of severe criticism ; their competence has not been disputed by 
 those qualified to judge. I cannot be required to stop and argue questions with 
 men who oppose their calculations who urge in opposition thereto, the figures of 
 men who have emerged suddenly from the walks of private life, for convenience 
 sake, to the dignity of Civil Engineers." Sound economy demands the employment 
 of the very best men for the popular and for the professional duties of the Levee ; 
 and these once employed, administrative vigor demands that they be treated with 
 the fullest confidence. Disparagement of the parties entrusted with those important 
 duties, will merely weaken their hands, diminish their efficiency ; and ought to be, 
 therefore, frowned down by the intelligent and judicious, unless, when based on 
 
132 PRINCIPLES AND PRACTICE OP 
 
 pride, his honest conviction, and his whole property at stake, 
 on the success of the Levees, an advanced man like the Com- 
 missioner for Coahoma ought not to be met, after the experi- 
 ence of the public in those works for fully seven years, with 
 narrow and silly objections to his employment of an Engineer. 
 Simple as thai operation of shovelling and loosening earth 
 undoubtedly is, the public in the Yazoo Valley, have not yet 
 realized the fact, that even that simple operation is an import- 
 ant subject of practical science. Millions of dollars national 
 wealth, and national advancement at stake on the shovelling, 
 loosening, and hauling of earth, many of the tax-payers behind 
 the Levee have yet to learn, or to value, the fact that even this 
 item in Leveeing, taken from the blind guidance of the rude 
 and wasteful suggestions of uninformed laborers, has been 
 placed under the infallible guidance of economic inductions 
 incorporated into a few practical laws. Leveeing, in fact, is in 
 every particular an art. It requires more scientific skill, 
 patient reflection, careful instrumentation, and, perhaps, even 
 more prac^icalr*knOwledge of earth-works and foundations, than 
 -ilfrequired in the Engineering of nine out of ten of the Kail- 
 roads of the country. Besides that, the Engineer entering on 
 such-dutie^, /takes the position in his profession on this Conti- 
 nent, of the pioneer of a new set of works, the classifier of a new 
 set of circumstances, the observer of a new set of phenomena ; 
 and consequently, to be professionally that is to say, econom- 
 ically successful as such pioneer, classifier, observer, must be 
 guided from the outset by all the lights of the practice of 
 water-works and of the science of fluids. Railroad Engineering 
 is a beaten track. Uniform in almost all its details, thatdepart- 
 ment of the profession involves, for the greater part, but a 
 mere knowledge of routine rules. Routine practice, then, will 
 constitute but a very poor qualification for a position, that like 
 
 unmistakable grounds that may be followed up to summary dismissal. No unfit 
 man should be retained ; no fit man should be for the promotion of some petty 
 interest damaged in his efficiency. 
 
EMBANKING LANDS FROM EIVER-FLOODS. 133 
 
 Leveeing, must make for itself its own rules of practice rules 
 that cannot be made by ever so thorough a knowledge of 
 mere routine, unaccompanied by a knowledge of the principles 
 of practical and scientific Engineering. Thoughtful intelligence, 
 then, appreciating the serious interests at stake in the effici- 
 ency of the Levees, instead of carping at the placing of the 
 professional duties of the Levee-system in the hands of a regu- 
 larly trained Engineer, in conjunction with the most able, 
 enlightened, and honest man to be found for discharging 
 the popular duties of the system, would rather have suggested 
 its serious apprehension that his acceptance of a salary so 
 small as $1500, place in a doubtful light the professional fit- 
 ness of the Engineer charged with duties so delicate and 
 responsible. The terrible lesson of the flood just subsiding, 
 will, however, force the property and the purpose of the 
 great Yalley to action action guided by all the lights of the 
 broadest and most liberal intelligence. It is, therefore, hoped 
 that, in order to sustain this expected action, some steps be 
 set on foot for freeing Levee-administration from the popu- 
 lar drawbacks upon its efficiency, by either raising it as far 
 as is practicable above local restraints, or, failing in that, by 
 enabling the popular intelligence controlling the whole sys- 
 tem, to keep pace with the growth of the importance of 
 that system. * 
 
 * The views of administration presented above, have been endorsed in the late 
 message of Governor McWillie, of Mississippi. In that able document, his Excel- 
 lency holds the following language : " This is a matter in which Mississippi is not 
 alone interested, even on her own Levees. All tho States, above and below her, 
 along the river bank from Cairo down, are subject to the same inundation, and mu- 
 tually act and react upon each other. The Levees of any one State are parts of a 
 chain of Levees ; and the direction, restraints, and flow, of the waters of the Missis- 
 sippi through, or past any State, are portions of the forces which affect its regimen 
 everywhere, but most strongly in the Counties below. * * * No elaborate plea is 
 necessary to prove the importance of having a Levee-system for the whole Valley of 
 the Mississippi, framed on sound principles of science, and in concert among tho 
 States interested." Change of administration widening and concert of the several 
 existing areas of administration are felt on all hands to be necessities, and the best 
 means of remedying this necessity practically is, undoubtedly, that of the District 
 Drainage system extended to the organization of a general council. 
 
134 PRINCIPLES AND PRACTICE OF 
 
 CHAPTER IX. 
 
 EARTH WORK CALCULATIONS. 
 
 The Prismoidal Formula constitutes the only rule by which 
 regularly sloped embankments can be measured correctly. 
 This rule is as follows : To the sectional area of each end add 
 four times the area of the middle section ; one-sixth of the result- 
 ing sum multiplied by the length of the prism, gives the solid 
 content. If lineal yards be the units employed in the calcula- 
 tion, the direct result of the rule will be cubic yards ; but if 
 lineal feet be the units employed in the calculation, then the 
 direct result of therule being cubic feet, must, to express itself 
 in cubic yards, be divided by 27. This formula supposes 
 the embankment to be a regular prism ; the actual height of 
 crown and width of base midways between the two ends, being 
 the arithmetical mean one-half the sum of the corresponding 
 heights and widths, respectively, of the two ends. The end 
 areas, then, must never exceed such limits as include between 
 them observable inequalities of ground the supposition of 
 the rule being that the end areas have been taken at intervals 
 sufficiently close to have broken the irregularities of the work 
 into a series of uniformly sloping prisms. The " sectional 
 area" referred to in the rule is the production of the arithmet- 
 ical mean half the sum of the width of crown and width of 
 base by the height. The 100 feet chain is that employed by 
 Engineers in order by taking the end areas, whenever practi- 
 cable at that distance asunder, to simplify the above prescribed 
 rule for multiplying by the length. This multiplication in the 
 

 
 EMBANKING LANDS FROM EIVER-FLOODS. 135 
 
 case of stations 100 feet asunder is made by removing the 
 decimal point two figures to the right ; or when multiplying a 
 whole number by the addition to it of two ' cyphers. Lineal 
 feet being generally the unit of measurement, the prismoidal 
 formula involves in general a division by 27 to reduce its result 
 to cubic yards ; and as it involves also a previous division by 
 6, it is somewhat of an abridgment when working it out in 
 detail to divide the sum of the end areas and four times the 
 middle area, after removing the decimal point two figures to 
 the right, by 162 six times twenty-seven. In order to explain 
 more clearly the working out of a measurement under the 
 prismoidal formula, let it be required to calculate the number 
 of cubic yards in a regular embankment 100 feet in length, ten 
 feet high at one end, and 4 feet high at the other end, the 
 crown having the uniform width of 5 feet, the base of the slopes 
 being proportional to the height as six to one. The base for 
 the end 10 feet high is (six times 10 for the slopes and 5 feet for 
 width of crown) 65 feet ; and one-half the sum the arithmet- 
 ical mean of the width of base and width of crown being 
 (65 and 5 divided by 2) 35, the product of the arithmetical 
 mean by the height (35 by 10) is 350, the area at the large end. 
 By a like process the sectional area for the small end is 
 68. The arithmetical mean one-half the sum of the heights at 
 both ends is (10 and 4 divided by 2) 7 the height of the 
 middle section. The area corresponding to this height, by the 
 calculation explained before, is 182 ; and this multiplied by 
 4 gives a product of 728 4 times the middle area. 350 (one 
 end area) and 68 (the other end area) and 728 (4 times the 
 middle area) show a total of 1146 ; and this multiplied by the 
 length being 114600, one-sixth of the product divided by 27 (or 
 114600 divided by 162) shows a quotient of 707.40, the content 
 of the embankment, in question, in cubic yards. To explain 
 this more clearly it is better to repeat the same calculation in 
 another form : 
 
136 PRINCIPLES AND PRACTICE OF 
 
 GREATER END. LESS END. 
 
 10 (height) 4 (height) 
 
 6 rate of slope, 6 rate of slope, 
 
 60 base of slopes, 24 base of slopes, 
 
 5 base of crown, 5 base of crown, 
 
 65 width of base, 29 width of base, 
 
 5 width of crown, 5 width of crown, 
 
 2)70 sum of widths, 2)34 sum of widths, 
 
 35 arithmetical mean, or half the 17 arithmetical mean, or half the 
 
 sum of the width of crown, sum of the width of crown, 
 
 and of base. and of base. 
 
 35 arithmetical mean width, 17 arithmetical mean width, 
 
 10 height, 4 height, 
 
 350 sectional area. 68 sectional area. 
 
 MEAN AREA. 
 
 10 height of greater end, 
 
 4 height of less end, 
 
 2)14 sum of the two heights. 
 
 7 mean height. 
 
 6 rate of slope, 
 
 42 base of slopes, 
 
 5 base of crown, 
 
 47 width of base, 
 5 width of crown, 
 
 2)52 sum of widths, 
 
 26 arithmetical mean or half the sum of 
 
 the width of crown and of base. 
 26 arithmetical mean width, 
 
 7 height, 
 
 182 sectional area, 
 4 multiplier, 
 
 728 four times the middle area. 
 
 SUMMATION. 
 
 350 area of greater end, 
 68 area of less end, 
 728 four times middle area 
 
 1146 aggregate of areas, 
 100 length, 
 
 6)114600 product of aggregate by length, 
 27)19100 content in cubic feet, 
 707.40 content in cubic yards. 
 
EMBANKING LANDS FROM RIVER-FLOODS. 137 
 
 This then is the full detailed method of earth-work estimation 
 in accordance with the prismoidal formula. Before offering any 
 further remarks on the subject, it is better to meet here the 
 prevailing practice of estimation among the unskilled men 
 charged with the " Engineering" of Levees, by some compari- 
 sons with the above the correct practice. The methods of 
 calculation in common use on all the Levees of both Arkansas 
 and Mississippi with the exception of those in Coahoma, 
 where Col. Alcorn has taken the trouble to acquire perfect 
 facility in the correct practice himself are those by average 
 heights and by average end areas. These systems are wrong in 
 principle ; but, in the popular spirit by which these remarks 
 have been guided, waving the error of principle, the most 
 effective corrective in the case will be an illustration of that 
 error in practice. The prismoidal formula has already been 
 worked out in detailing the measurement of a Levee ten feet 
 at one end and four feet high at the other end, the width of 
 crown being uniformly 5 feet ; and the aggregate rate of side 
 elopes 6 to 1. The content of this embankment will now be 
 detailed according to the two rules of measurement pursued 
 generally on the Mississippi : 
 
 BY AVERAGE HEIGHTS. 
 
 10 height at greater end, 182 area for average height, 
 
 4 height of less end, 100 length, 
 
 2)14 sum of heights, 27)18200 content in cubic feet, 
 
 7 average height, 674.00 content in cubic yards. 
 
 6 rate of slope, 
 
 BY AVERAGE AREAS, 
 
 42 base of slopes, 
 
 5 base of crown, 350 area of greater end, 
 
 68 area of less end. 
 47 width of base, 
 5 width of crown, 2)418 sum of areas, 
 
 2)52 sum of widths, 209 average area, 
 
 100 length, 
 26 half sum of widths. 
 
 7 average height, 27)20900 content in cubic feet, 
 
 182 area for average height, 774.00 content in cubic yards. 
 
138 PRINCIPLES AND PRACTICE OP 
 
 By this method of average heights, then, the solid content of 
 the embankment in question, would be taken at 674 cubic 
 yards ; and by the method of average areas at 774 cubic yards ; 
 a difference that at fifteen cents a yard, showing a discrepancy 
 of $15 for 100 feet of Levee, would sum up at the same rate to 
 an immense sum when repeated for every 100 feet along the 
 whole extent of even a County. But the fact of the case is ; 
 both of the quantities are wrong ; and the one that by aver- 
 age areas being wrong in its excess, is an injustice to the 
 tax-payer, while the other that by average heights being 
 wrong in its deficiency, is an injustice to the contractor. The 
 true quantity, as given in accordance with the prismoidal for- 
 mula, has been shown in detail to be 707 cubic yards. The 
 quack-systems then, and the correct system, compare in the 
 case under consideration as follows : 
 
 674 cubic yards the content by average heights. 
 
 707 cubic yards the content in fact. 
 
 774 cubic yards the content by average area. 
 
 One of the common systems, then, of calculation by average 
 heights is an injustice in the instance under consideration, at 
 the rate of $261 per mile to the Levee contractor ; the other 
 and equally common system is an injustice in the same instance 
 at the rate of $531 per mile to the Levee-tax-payer. This 
 assumes the cost of the work at 15 cents per cubic yard. The 
 error of these modes of calculation are sometimes less than in 
 the case presented above ; but they are also, sometimes, even 
 still greater : with end-areas and end-heights nearly equal, 
 they are very trifling ; but with end-areas and end-heights 
 differing largely, those errors become very serious. For the 
 width of crown and rate of base adopted in the above exam- 
 ple, the excess of result, according to the system of average 
 areas for example, increases over the true content of the prism 
 according to the following gradations : for lengths of 100 feet, 
 
EMBANKING LANDS FROM RIVER-FLOODS. 139 
 
 where the inequality of the heights of the two ends is/ 
 
 1 foot, the excess given by the method of average areas, is 1.6 cubic yards. 
 
 2 feet, do do 7.5 cubic yards. 
 
 3 feet, do do 17.0 cubic yards, 
 
 4 feet, do do 30.0 cubic yards. 
 
 5 feet, do do 46.0 cubic yards. 
 
 6 feet, do do 66.6 cubic yards. 
 
 7 feet, do do 90.7 cubic yards. 
 
 8 feet, do do 118.5 cubic yards. 
 
 Adopting still the five-feet crown and six-fold base, the insuffi- 
 ciency of the quantities resulting from the process of average 
 heights, follows the following gradations : with a length of 100 
 feet where the inequality of the heights of the two ends is, 
 
 1 foot, the deficiency by the method of average heights, is 0.8 cubic yards. 
 
 2 feet, do do 3.7 cubic yards. 
 
 3 feet, do do 8.5 cubic yards. 
 
 4 feet, do do 15.0 cubic yards. 
 
 5 feet, do do 23.0 cubic yards. 
 
 6 feet, do do 33.3 cubic yards. 
 
 7 feet, do do 45.4 cubic yards. 
 
 8 feet, do do 59.3 cubic yards. 
 
 It may be noted here that the calculations by average Jmghts are 
 always a wrong to the contractor , those by the average area 
 being always a wrong to the public the deficiency in the one 
 case being one-half that of the excess in the other case. But, 
 bad as are both of those methods when applied to even short 
 lengths of embankment, a very common practice in the use of 
 both, by extending the averages to considerable lengths, make 
 the evil still greater. The following table shows the heights, 
 crown, and base of a Levee, taken at regular intervals of 
 100 feet ; extracted from a measurement-book of my own prac- 
 tice on Levees, it represents an actual state of facts. The 
 last column shows the content of each 100 feet of the embank- 
 ment, according to the prismoidal formula the true content 
 in cubic yards. 
 
140 
 
 PRINCIPLES AND PEACTICE OF 
 
 Stakes. Heights. 
 
 Widths. 
 
 Contents in 
 cubic yards 
 
 Crown. | Base. 
 
 1210 
 
 3.36 
 
 5 
 
 20.16 
 
 
 
 1211 
 
 2.59 
 
 5 
 
 15.54 
 
 124.9 
 
 1212 
 
 1.77 
 
 5 
 
 10.60 
 
 74.3 
 
 1213 
 
 1.60 
 
 5 
 
 9.60 
 
 47.5 
 
 1214 
 
 1.43 
 
 5 
 
 8.58 
 
 39.2 
 
 1215 
 
 1.80 
 
 5 
 
 10.80 
 
 43.7 
 
 1216 
 
 2.52 
 
 5 
 
 15.12 
 
 71.8 
 
 1217 
 
 1.74 
 
 5 
 
 10.44 
 
 71.4 
 
 1218 
 
 3.00 
 
 5 
 
 18.00 
 
 85.0 
 
 1219 
 
 3.72 
 
 5 
 
 22.32 
 
 156.1 
 
 1220 
 
 3.18 
 
 5 
 
 19.08 
 
 164.5 
 
 1221 
 
 3.91 
 
 5 
 
 23.46 
 
 173.6 
 
 1222 
 
 3.73 
 
 5 
 
 22.38 
 
 196.4 
 
 1223 
 
 3.63 
 
 5 
 
 21.78 
 
 186.3 
 
 1224 
 
 2.60 
 
 5 
 
 15.60 
 
 137.1 
 
 1225 
 
 1.96 
 
 5 
 
 11.76 
 
 79.9 
 
 1226 
 
 6.28 
 
 5 
 
 37.68 
 
 243.0 
 
 1227 
 
 9.40 
 
 5 
 
 56.40 
 
 7ti6.2 
 
 1228 
 
 7.58 
 
 5 
 
 45.48 
 
 884-5 
 
 1229 
 
 12.38 
 
 5 
 
 74.28 
 
 1225.1 
 
 1230 
 
 11.26 
 
 5 
 
 67.56 
 
 1659.8 
 
 1231 
 
 8.69 
 
 5 
 
 52.14 
 
 1207.8 
 
 1232 
 
 10.23 
 
 5 
 
 61.38 
 
 1283.9 
 
 1233 
 
 8.66 
 
 5 
 
 51.96 
 
 1082.2 
 
 1234 
 
 7.66 
 
 5 
 
 45.96 
 
 814.4 
 
 1235 
 
 7.49 
 
 5 
 
 44.94 
 
 704.7 
 
 1286 
 
 8.50 
 
 5 
 
 51.00 
 
 786.1 
 
 1237 
 
 8.74 
 
 5 
 
 52.44 
 
 003.1 
 
 1238 
 
 7.47 
 
 5 
 
 44.82 
 
 805.6 
 
 1239 
 
 6.12 
 
 5 
 
 36.72 
 
 577.1 
 
 1240 
 
 3.04 
 
 5 
 
 18.24 
 
 285.3 
 
 1241 
 
 2.10 
 
 5 
 
 12.60 
 
 97.2 
 
 1242 
 
 1.75 
 
 5 
 
 10.50 
 
 60.0 
 
 1243 
 
 1.63 
 
 5 
 
 9.78 
 
 47.9 
 
 1244 
 
 1.76 
 
 5 
 
 10.56 
 
 47.9 
 
 1245 
 
 2.09 
 
 5 
 
 12.54 
 
 60.0 
 
 1246 
 
 2.22 
 
 5 
 
 13.32 
 
 71.4 
 
 ]247 
 
 3.49 
 
 5 
 
 2C.94 
 
 118.3 
 
 12-18 
 
 3.47 
 
 5 
 
 20.82 
 
 167.9 
 
 1249 
 
 3.43 
 
 5 
 
 20-58 
 
 164.4 
 
 1250 I 
 
 3.42 
 
 5 
 
 20-52 
 
 160.7 
 
 Total cubic yards, .... 15,670.2 
 
 The true content of the above Levee 4,000 feet long was 
 15676 cubic yards. Now, the average height of all the stations 
 on this piece of work was, as may be seen by adding up the 
 above column of heights, and dividing the sum by the number 
 of heights so added, 4.67 feet. The average width correspond- 
 ing to the average height, being 16.51 feet, the area the 
 product of this average height by its average width is 77.10 
 square feet. To repeat this in another form : 
 
 16.51 the average width corresponding to a height of 4.67 feet. 
 4.67 the average height of the whole embankment. 
 
 77.10 the average area by a general average height of the whole bank. 
 4000 the length of the whole bank. 
 
 27)308400, content of whole bank in square feet. 
 11422.22, content of whole bank in cubic yards. 
 
EMBANKING LANDS FROM RIVER-FLOODS. 141 
 
 The comparison in this instance then, stands thus : 
 
 15672 cubic yards, the true content. 
 
 11422 cubic yards, the content by a general average height. 
 
 4250 cubic yards of error against contractor. 
 
 The contractor, in this instance, paid nominally, 15 cents per 
 yard for his work, would, in fact, be paid according to this sys- 
 tem of measurement, at the rate per yard of less than 11 cents. 
 The contractor, however, is generally able to secure fair play 
 for himself ; but in the case of those methods of calculation 
 that, pursued as they are by officers of the public, give the 
 contractor a large excess above his just rights, there is no pro- 
 tection to save that public, when it contracted for but 15 cents 
 a yard, from paying, in consequence of the unfitness of its own 
 officer its " Engineer" so high, in fact, as even 20 cents a 
 yard. So important is it to both the contractor on Levees, and 
 to the public paying for their construction, that a system of 
 measurement be laid down that, adapted to the popular under- 
 standing., may secure to both parties mutual, even-handed 
 justice. .' f . ' t *r J ; 
 
 The errors of the systems common in measuring Levees thus 
 exposed, attention may be now recalled to the prismoidal rule. 
 The illustration given of that rule willhave suggested that its 
 employment at intervals of 100 feet, and of less, along a line- of 
 Levee, makes correct estimation, a process most elaborate and 
 tedious. Practice, however gives a surprising expertness in 
 casting up quantities directly ; and also in the use of regular 
 forms of calculation, suggests from time to time several meth- 
 ods of abridgement. For a regular rate of slope, for instance, 
 the Engineer about to estimate any considerable stretch of 
 work, finds it much more correct and rapid to calculate, in the 
 first place, a regular table for that slope ; and applying that 
 table to the special dimensions of his measurement, take off 
 prismoid after prismoid, by inspection. For new Levees such 
 
142 PRINCIPLES AND PRACTICE OF 
 
 a table is directly applicable. Tables 1, 2, and 3, have, accord- 
 ingly, been added at the end of these remarks, for the use of 
 the less expert and indeed, also, of the more expert to whom 
 the elaboration necessary, otherwise, may be an obstacle to 
 the general introduction in Levee-measurement of the pris- 
 moidal formula. These calculations are intended to cover all 
 the forms of section prevailing in the Levee-practice of the 
 Mississippi. In terms representing cubic yards, the tables 
 show, for prisms of 100 feet long, the " end area," and 
 " four times middle area" for all heights to tenths and half 
 tenths of a foot, from a height of one foot to a height of 24.95 
 feet. Table No. 1 is estimated for a base-width of 6 feet hori- 
 zontal to 1 foot vertical ; and with a crown of 5 feet wide 
 the dimensions allowed by the Superior Board of Levee 
 Commissioners for the State of Mississippi. Table No. 2 is 
 estimated for a base, bearing the same constant proportion to 
 the height ; but differing from table No. 1 in having a crown of 
 only 3 feet wide. No. 3 gives the quantities under the same 
 heads, in the same terms, and for the same intervals, for a Levee 
 having a crown of 3 feet across ; but with a base having a 
 width of seven times the height. The dimensions given in this 
 table, are those generally used in the State of Arkansas, with 
 the exception of the width of crown ; the adopted crown-width 
 being, as before remarked, erroneous in principle. In measur- 
 ing the Levee it is, in fact, not practicable to arrive at a greater 
 accuracy in the heights than a tenth of a foot. The tables are 
 accordingly, in being extended to tenths, carried out to the full- 
 est detail available in practical estimation. In order to show 
 in juxta-position a calculation made in detail, and the same 
 made under the abridging of the above table, let it be proposed 
 to cast up the quantities in a Levee 100 feet long, 3.60 feet in 
 height at the less end, and 7.70 feet in height at the greater 
 end, the base being always six times the height, and the crown 
 of the uniform width of 5 feet. 
 
EMBANKING LANDS FROM RIVER-FLOODS. 143 
 
 PRISMOIDAL FORMULA WORKED OUT IN DETAIL. 
 
 GREATER END. LESS END. 
 
 7.70 height, 3.60 height, 
 
 6 multiple for base, 6 multiple for base, 
 
 46.20 width of base, 21.60 width of base, 
 
 6.00 width of crown, 5.00 width of crown, 
 
 2)51.20 sum of width, 2)26.60 sum of width, 
 
 25.60 mean or half sum of width 13.30 mean or half sum of width, 
 
 7.70 height, 3.60 height, 
 
 179200 79800 
 
 1792 399 
 
 197.1200 sectional area. 47.8800 sectional area. 
 
 MIDDLE AREA. 
 
 7.70 height at greater end. 
 3.60 height at less end, 
 
 2)11.30 sum of heights 
 
 5.65 mean or half sum of heights, 
 6 multiple for base, 
 
 33.90 width of base, 
 5.00 width of crown. 
 2)38.90 sum of width. 
 
 19.45 mean or half sum of widths, 
 5.65 mean height, 
 
 9725 
 11670 
 9725 
 
 109.8925 middle area. 
 
 4 multiple according to rule, 
 
 439.57 four times middle area, 
 197.12 area at greater end, 
 47.88 area at lesser end. 
 
 6)68457 sum of areas, 
 
 114.095 one-sixth the sum of areas, 
 100 length. 
 
 27)114095 (422.6 solid content in cubic yards. 
 108 
 
 60 
 54 
 
 69 
 54 
 
 155 
 
 162 
 
144 PRINCIPLES AND PRACTICE OP 
 
 Such is the regular working out of this quantity in detail. 
 Let it now be worked out by the tables. The crown being five 
 feet and the base six times the height, the table to be employed 
 in the case is No. 1. Turning then to No. 1, under the head of 
 three feet and on the line corresponding to the decimal .60 in 
 the margin, the tabular "end area " corresponding to 3.60 is 
 found to be 29.6 ; under the head of 7 feet and on the line of 
 the marginal decimal .70, the end area in the table is 121.7. 
 Adding together 3.60 the height at one end, and 7.70 the height 
 at the other end, the aggregate is 11.30 ; and this sum divided 
 by 2 shows for the middle height, 5.65 feet. Turning again to 
 the table, the tabular number under the head 5 feet, and on the 
 line .65, is found in the column of " middle areas " to be 271.4. 
 Adding 271.4 (four times the middle area) 29.6 (the area at the 
 less end) and 121.7 (the area at the greater end) the total is 
 422.7. This explanation of the use of the tables thus given, the 
 comparison with the above detail may be now commenced. 
 
 3.60 less height tabular " end area" corresponding, - - 29.6 
 7.70 greater height tabular " end area" corresponding, - - 121.7 
 
 2)11.30 sum of heights. 
 
 6.65 middle height tabular " 4 times middle area" corresponding, 271.4 
 Solid content, by prismoidal formula, in cubic yards, - - 422.7 
 
 The figures in each process show at a glance the facilities fur- 
 nished by the table the detail process requiring 208 figures, 
 and tabular abridgement but 29 figures. The tables, then, may 
 be held as reducing the time and labor of calculations by the 
 prismoidal formula to one-seventh the time and labor neces- 
 sary in carrying out that formula in detail. These tables are 
 altogether new the result of using the formula extensively 
 when cutoff from an opportunity of reference to any other 
 system of calculation by inspection. Original in every partic- 
 ular as they are, it is, perhaps, better to explain more fully 
 than has been done in the foregoing comparison, the use and 
 
EMBANKING LANDS FEOM RIVER-FLOODS. 
 
 145 
 
 convenience of those tables. Passing to this explanation, it 
 may be observed that the quantities employed in the table are 
 fictitious, representing no real quantity, until the summation 
 into a solid content, when they take the form of cubic yards. 
 Extracting the heights at each station from the level-book, 
 these are transferred, in the office, to the measurement-book 
 in the following manner. The column showing the distances 
 between the several stations (see annexed form) are to be filled 
 up with those distances, leaving every second line blank. The 
 heights, respectively, corresponding to those distances are 
 then transferred to the column of heights, each opposite its 
 own distance, and consequently entered, like the distances, on 
 every second line. The third column of the measurement-book 
 is next filled in with the quantity constituting an arithmetical 
 
 Form of Measurement Book adapted to Tables JSfos. I., II., and III. 
 
 Distance 
 Station. 
 
 End 
 
 Heights. 
 
 Mean 
 Heights. 
 
 Tabular 
 
 Number. 
 
 Contents in 
 Cubic Yards. 
 
 Remarks. 
 
 
 
 100 
 200 
 300 
 400 
 500 
 13 feet 
 
 5.00 
 5.20 
 5.80 
 5.80 
 5.70 
 7.20 
 19.60 
 
 5.10 
 
 54.1 
 224.2 
 58.1 
 258.0 
 71.8 
 262.4 
 C0.2 
 258.0 
 69.0 
 848.0 
 107.1 
 1412.8 
 741.7 
 
 836.4 
 887.4 
 893.9 
 887.2 
 624.1 
 294.0 
 
 58.1 belonging to this pris- 
 moid is included therein, 
 and belonging also to the 
 following, is included in 
 that, too. 
 
 Special calculation. 
 
 5.50 
 5.55 
 5.50 
 6.45 
 
 13.40 
 
 mean between each pair of heights entered in the second col- 
 umn this mean being, of course, one-half the sum of its 
 corresponding pair of end-heights. These mean heights are 
 entered in the lines that had been left blank, when filling in 
 the first and second columns ; and thus occupy, in the mea- 
 surement-book, a place between the two heights, from which 
 each of them is deduced. The end-heights, and mean heights 
 thus filled in and placed in proper position in the measure- 
 ment-book, the calculator will next call to his assistance the 
 
146 PRINCIPLES AND PRACTICE OF 
 
 earth-work tables. In doing this, it must be recollected that 
 each set of heights in the tables, having corresponding to it 
 two different sets of quantities that in the column of " end- 
 areas," and that in the column of " 4 times the middle height' ' 
 the only certain mode of guarding against the use of one of 
 these for the other, is to first take out the quantities under one 
 head those for the measurement-column of '"end-heights," first j 
 and all these completed, then take out the quantities under the 
 other head those for the measurement-column of " mean 
 heights." The first " end-height," then, is 5.00. Turning to 
 table No. 1, the eye rests on the head in large characters 
 " 5 feet." Running down the margin, the decimal " 00" is 
 seen ; and the " end-areas" under the heading " 5 feet" on line 
 " 00" is found to be 54.0. Under the head, Tabular numbers 
 of the measurement-book, this 54.0 is then entered on the line 
 running across the book from the end-height 5.00. The head- 
 ing " 5 feet," being again used in the tables, the eye rests in 
 the next place on the marginal decimal .20 ; and the " end- 
 area" under the head " 5 feet," corresponding to the decimal 
 .20, is seen to be 58.1. The 58.1 is, then, entered in the col- 
 umn of " tabular numbers" of the measurement-book, on the 
 line running across the book from the corresponding height of 
 5.20. So, also, with all the other " end-heights." These com- 
 pleted, the next duty is to take out the tabular numbers for 
 the "mean heights." These, be it remembered, are found in 
 the column " 4 times middle area." The first mean height in 
 the above form of measurement-book, is 5.10. Again, under 
 the head " five feet," after running down the margin to the 
 decimal .10, the eye rests on the tabular number corresponding 
 to 5.10 in the column ' ; 4 times the middle area." This num- 
 ber is seen to be 224.2. Opposite to, and on the line running 
 across the measurement-book from, " mean height" 5.10, this 
 number, 224.2 is next entered in the column of tabular num- 
 bers. The mean heights are thus gone through, one after the 
 
EMBANKING LANDS FROM RIVER-FLOODS. 147 
 
 other. The use of the tables ended, the next step is the sum- 
 mation. This must be done by grouping together each three 
 quantities in the column of " tabular numbers" always taking 
 care that, after that quantity corresponding to the first distance 
 the quantity corresponding in the column of " tabular num- 
 bers" to each distance, or to each " end height," shall be used 
 in the additions twice once, in addition to the two quantities 
 above it, and again, in addition to the two quantities l>dow it, 
 in the measurement-book. The column " content in cubic 
 yards" thus made out for each distinct prism, the addition of 
 oil completes the measurement. This supposes the stations, 
 it will be observed, separated by uniform distances of 100 feet 
 each. In irregular ground, however, the stations must be 
 separated by irregular intervals in bayous, for instance, it 
 being often necessary to place them so close together as 4 or 
 5 feet. The measurement-book in such cases is filled, as shown 
 between stations 4 and 5 in the above form, the prisms being 
 made subjects of special calculations. These calculations may 
 be made with a saving of time and trouble by adding the tabu- 
 lar numbers corresponding to its end-heights, and to its mean 
 height as described for the 100 feet lengths ; and multiplying 
 the sum of these numbers by the length of the short prism in 
 question ; the removal of the decimal in the product, two fig- 
 ures to the left, will give the true content of that prism. 
 Suppose, for illustration, a prismoid of 13 feet length, 7.20 feet 
 at one end, and 19.60 feet at the other end. This has a mean 
 height of (one-half the sum of its end-heights) 19.60 added to 
 7.20, and the sum divided by 213.40. 
 
 7.20 end height has a tabular " end area" of - 107.1 
 
 19.60 end height has a tabular end'area of - - - - 741.7 
 13.40 mean height has a tabular " 4 times middle area" of - 1412.8 
 
 Total, . - 2261.6 
 Multiplied by length - 13 
 
 Cubic yards in the 13 feet prism - - 294.00.8 
 
148 PRINCIPLES AND PRACTICE OF 
 
 This will save some trouble, as otherwise the calculation for 
 the 13 feet must be made under the formula in extenso. The 
 remaining quantities in the above form of measurement are 
 obtained in the same manner as those of the foregoing expla- 
 nations. The quantities of embankments having a crown of 
 3 feet across and a base of six-fold width, are to be calculated 
 by table No. 2. A seven- fold width of base having a crown of 
 3 feet wide presents a section whose quantities must be calcu- 
 lated by table No. 3. The use of these two tables is precisely 
 similar to that of table No. 1. 
 
 Tables 1, 2, and 3 are confined in their application to new or 
 well preserved embankments. Old Levees, however, with 
 worn crowns, hollowed sides, and spread bases, cannot be meas- 
 ured with any approach to truth by a rule based on a uniform 
 width of crown and constant rate of base. Estimation under 
 such circumstances can be made only by a series of careful 
 cross-sectioning ; and in order, therefore, to meet this necessity 
 of the present works in Levee management, a table of contents 
 is added here on the basis of sectional areas. Table No. 4 aims 
 at this object. Irregular works being the special subject for 
 the use of this table, it may be necessary to observe that it is 
 equally applicable to works of uniform sections. The rule for 
 using table No. 4 is as follows : For lengths of 100 feet add 
 to the cubic yards corresponding in the table to each of the given 
 end areas, 4 times the cubic yards corresponding to the mean of 
 those two areas, and the sum will be the content of the bank in 
 cubic yards. Or another rule for using table No. 4 : Add for 
 lengths of WO feet the two end areas to 4 times the mean of those 
 two end areas, and the number corresponding in the table to the 
 total of these is the content of the bank in cubic yards. For 
 shorter lengths than 100 feet, multiply the result in either of 
 the above rules by the length, and changing the decimal point 
 two figures to the left, the product is the content in cubic yards. 
 The sectional areas in the tables are given, it may be observed, 
 
EMBANKING LANDS FROM RIVER-FLOODS. 
 
 149 
 
 in square feet. Taking a few of the prismoids in the form of 
 measurement-book already given, the sectional areas are as 
 follows, as estimated by table No. 4 : 
 
 Form of Measurement- Book for Table No. IV. 
 
 
 
 WIDTHS. 
 
 
 
 
 
 
 
 
 Sectional 
 
 
 Contents in 
 
 Strikes. 
 
 Height. 
 
 Crown. 
 
 Base. 
 
 Average 
 widths. 
 
 Areas. 
 
 Mean Area. 
 
 Cubic Yards. 
 
 
 
 5.00 
 
 5 
 
 80.00 
 
 IT. 50 
 
 8T.50 
 
 
 
 
 
 
 
 
 
 90.81 
 
 
 i 
 
 5.20 
 
 5 
 
 81.20 
 
 ^18.10 
 
 94.12 
 
 
 836.8 
 
 
 
 
 
 
 
 104. TT 
 
 
 2 
 
 5.80 
 
 5 
 
 84.80 
 
 19.90 
 
 115.42 
 
 
 888.0 
 
 
 
 
 
 
 
 106. 4T 
 
 
 3 
 
 5.30 
 
 5 
 
 81.80 
 
 18.40 
 
 9T.52 
 
 
 894.0 
 
 
 
 
 
 
 
 104.62 
 
 
 4 
 
 5. TO 
 
 5 
 
 34.20 
 
 19.60 
 
 111.T2 
 
 
 88T.4 
 
 
 1 
 
 
 
 
 
 
 First prismoid less end area 87.50 
 
 greater end area 94.12 
 
 4 times middle area 363.24 
 
 Total 544.86 
 
 The solid content corresponding in table No. 4 to this aggre- 
 gate " area" 544.86 is 336.4 cubic yards. 
 
 Second prismoid less end area 94.12 
 
 greater end area 115.42 
 
 4 times mean area 419.08 
 
 Total 
 
 628.62 
 
 Running the eye down the column " areas in square feet " of 
 table No. 4, it rests on the large figures 620 ; and following 
 down the column to the single figure 8, the number corres- 
 ponding to 628 is seen to be 387.6. By the aid of the auxil- 
 iary table subjoined to table 4 the proportional value in cubic 
 yards corresponding to the decimal of the areas, .62 is to be 
 added to the solid content of the whole numbers. The cubic 
 yards corresponding to the aggregate area of 628.62 shows, 
 therefore, a solid content of 388.0 cubic yards. This explanation 
 is sufficient to make the use of table No. 4 perfectly clear. For 
 
150 PRINCIPLES AND PRACTICE OF 
 
 the particular measurements contemplated by this table it will 
 be found a most valuable assistant to the calculator who aims 
 at close and careful calculation. 
 
 All the tables in this book are new to the profession ; tables 
 1, 2, and 3, being modifications from the practice of Mr. M. Butt 
 Hewson ; table No. 4 being, however, purely original. Tables 
 Nos. 1, 2 and 3, respectively, condense in a small sheet con- 
 taining 60 lines and 16 columns, a number of results in cubic 
 yards that cannot, in the ordinary diagonal tables of earth- works, 
 be given in a smaller space than that occupied by 480 lines and 
 480 columns. Earth-work tables in general, limit their facilities 
 to heights of full feet ; and therefore, tables 1, 2, and 3, an- 
 nexed to this, w 7 hile much more condensed in form and much 
 more facile of reference, make a great advance in going into 
 detail so minute as that involved in heights of feet and tenths 
 of a foot. It is perhaps unnecessary to state that all these tables 
 are equally applicable to cut and to bank, whether on Levee, 
 Canal or Railroad. 
 
 In conclusion it may be added that these remarks, whether 
 in theory or in practice, have been of necessity generalities. 
 Engineering on Levees is in the crude state of those improve- 
 ments, work for a man of some original observation, some 
 original resources, some scientific and practical skill. Correct 
 measurement will be brought by the remarks made above 
 within the compass of men of intelligence under ordinary 
 circumstances but the special circumstances for even separa- 
 ting Levee-practice from general rules spreading of base, 
 sinkings of foundations, bulgings of sides, inundating of work- 
 pits, &c. make it necessary for proper estimation of those 
 works that they be always placed in the charge of some on e 
 thoroughly conversant with the elementary principles of meas- 
 urement. Location alone involves so many delicate and intri- 
 cate considerations these again involving so many serious if 
 not fatal contingencies as to require, superior to all rules of 
 
. 
 EMBANKING LANDS FROM RIVER-FLOODS. 151 
 
 practice the eye and mind of a professional Engineer. The 
 detail surveys suggested above are undertakings, too, that in 
 the hands of even a decent pretender to professional ability will 
 result in a simple waste of money. The Trigonometrical 
 survey for connecting the Levees on both sides of the River is 
 a duty from which (let unfitness be ever so ready to undertake 
 it) even the regular Engineer, who has never directed his 
 mind or his practice to such a system of survey, will be found 
 in honor and self-consciousness to decline. Finally : if any- 
 thing that has been said here shall further the interests of 
 Levees, shall bring those works more thoroughly within the 
 rules of art, shall strengthen the hands of the administrator 
 entrusted with their charge, or shall correct errors of opinion 
 on the part of planters and others hampering the intelligence 
 of his aims, the writer shall have felt rewarded with the satis- 
 faction of having left the impress of his experience in the 
 great Yalley after him as a souvenir for the benefit, in a greater 
 or less degree, of the very highest interests of a generous 
 people, amongst whom he has spent many a happy day of work 
 and pleasure. 
 
 THE END. 
 
TABLES 
 Nos. 1, 2, 3, and 4. 
 
154 
 
 PRINCIPLES AND PRACTICE OF 
 
 TABLE I. 
 
 Table of cubic yards corresponding to a cross section 
 
 Decimals of 
 a foot. 
 
 End 
 areas. 
 
 4 times 
 middle 
 area. 
 
 End 
 areas. 
 
 4 times 
 middle 
 area. 
 
 End 
 areas. 
 
 4 times 
 middle 
 area. 
 
 End 
 areas. 
 
 4 times 
 middle 
 area. 
 
 Decimals of 
 afoot. 
 
 
 1 
 
 foot. 
 
 2 
 
 feet. 
 
 3 
 
 feet. 
 
 4 
 
 feet. 
 
 
 .00 
 
 8.4 
 
 13.6 
 
 10.5 
 
 42.0 
 
 21.2 
 
 84.8 
 
 35.8 
 
 143.2 
 
 .OO 
 
 .05 
 
 8.7 
 
 14.7 
 
 10.9 
 
 43.8 
 
 21.9 
 
 87.6 
 
 866 
 
 146.5 
 
 .05 
 
 .10 
 
 8.9 
 
 15.8 
 
 11.4 
 
 45.6 
 
 22.6 
 
 90.3 
 
 37.5 
 
 149.8 
 
 .10 
 
 .15 
 
 4.2 
 
 16.9 
 
 11.9 
 
 47.6 
 
 23.2 
 
 93.0 
 
 883 
 
 153.3 
 
 .15 
 
 .20 
 
 4.5 
 
 18.1 
 
 12.4 
 
 49.4 
 
 23.9 
 
 95.6 
 
 89.2 
 
 156.6 
 
 .20 
 
 .25 
 
 4.8 
 
 19.4 
 
 12.8 
 
 51.4 
 
 24.6 
 
 98.3 
 
 40.1 
 
 160.6 
 
 .25 
 
 .30 
 
 5.2 
 
 20.7 
 
 13.4 
 
 53.4 
 
 253 
 
 101.0 
 
 40.9 
 
 163.5 
 
 .30 
 
 .85 
 
 5.5 
 
 21.9 
 
 13.8 
 
 55.4 
 
 25.9 
 
 103.8 
 
 41.7 
 
 167.0 
 
 .85 
 
 .40 
 
 5.8 
 
 23.2 
 
 14.4 
 
 57.5 
 
 26.7 
 
 106.6 
 
 42.6 
 
 170.6 
 
 .40 
 
 .45 
 
 6.1 
 
 24.5 
 
 14.9 
 
 59.6 
 
 27.4 
 
 109.5 
 
 43.5 
 
 174.2 
 
 .45 
 
 .50 
 
 6.5 
 
 25.9 
 
 15.4 
 
 61.7 
 
 28.1 
 
 112.4 
 
 44.4 
 
 177.8 
 
 .50 
 
 .55 
 
 6.8 
 
 27.8 
 
 16.0 
 
 63.9 
 
 28.9 
 
 115.5 
 
 45.3 
 
 181.4 
 
 .55 
 
 .60 
 
 7.2 
 
 28.8 
 
 16.5 
 
 66-1 
 
 29.6 
 
 118.2 
 
 463 
 
 185.1 
 
 .60 
 
 .65 
 
 7.6 
 
 30.8 
 
 17.1 
 
 68-4 
 
 80.3 
 
 121.2 
 
 472 
 
 188.9 
 
 .65 
 
 .70 
 
 8.0 
 
 81.9 
 
 17.7 
 
 70-6 
 
 81.1 
 
 1242 
 
 48.2 
 
 192.6 
 
 ,7O 
 
 .75 
 
 8.4 
 
 as.5 
 
 18.2 
 
 73.0 
 
 31.8 
 
 127.3 
 
 49.1 
 
 196.5 
 
 .75 
 
 .80 
 
 8.8 
 
 85.1 
 
 18.8 
 
 75.4 
 
 32.6 
 
 130.4 
 
 50.1 
 
 200.3 
 
 .80 
 
 .85 
 
 9.2 
 
 86.8 
 
 19.4 
 
 77.8 
 
 83.4 
 
 133.6 
 
 51.0 
 
 204.2 
 
 .85 
 
 .90 
 
 9.7 
 
 8S.5 
 
 20.1 
 
 80.2 
 
 842 
 
 136.7 
 
 52.0 
 
 208.2 
 
 .90 
 
 .95 
 
 10.0 
 
 40.2 
 
 20.6 
 
 82.5 
 
 35.0 
 
 140.0 
 
 53.0 
 
 212.1 
 
 .95 
 
 
 5 
 
 feet. 
 
 6 
 
 feet. 
 
 7 
 
 feet. 
 
 8 
 
 feet 
 
 
 .OO 
 
 54.0 
 
 216.1 
 
 75.9 
 
 803.7 
 
 101.5 
 
 406.2 
 
 130.9 
 
 523.5 
 
 .OO 
 
 .05 
 
 55.0 
 
 220.1 
 
 77.1 
 
 808.5 
 
 102.9 
 
 411.7 
 
 132.4 
 
 529.7 
 
 .05 
 
 .10 
 
 56.0 
 
 224.2 
 
 78.8 
 
 813.3 
 
 104.3 
 
 417.3 
 
 184.0 
 
 536.0 
 
 .10 
 
 .15 
 
 57.0 
 
 228.2 
 
 79.5 
 
 318.1 
 
 105.7 
 
 422.8 
 
 1.35.6 
 
 542.3 
 
 .15 
 
 .20 
 
 58.1 
 
 232.4 
 
 80.8 
 
 823.0 
 
 107.1 
 
 428.4 
 
 137.2 
 
 548.7 
 
 .20 
 
 .25 
 
 59.1 
 
 236.6 
 
 82.0 
 
 327.9 
 
 108.5 
 
 434.1 
 
 138.8 
 
 555.1 
 
 .25 
 
 .30 
 
 60.2 
 
 240.8 
 
 83.2 
 
 332.9 
 
 110.0 
 
 439.8 
 
 140.4 
 
 561.5 
 
 .30 
 
 .85 
 
 61.2 
 
 245.0 
 
 84.5 
 
 337.9 
 
 111.4 
 
 445.5 
 
 142.0 
 
 568.0 
 
 .35 
 
 .40 
 
 62.8 
 
 249.3 
 
 85.7 
 
 342.9 
 
 112.8 
 
 451.3 
 
 143.6 
 
 574.5 
 
 .40 
 
 .45 
 
 63.4 
 
 258.7 
 
 87.0 
 
 848.0 
 
 114.3 
 
 457.1 
 
 145.3 
 
 581.1 
 
 .45 
 
 .50 
 
 64.5 
 
 258.0 
 
 88.8 
 
 353.1 
 
 115.7 
 
 463.0 
 
 146.9 
 
 587.7 
 
 .50 
 
 .55 
 
 65.6 
 
 262.4 
 
 89.5 
 
 858.2 
 
 117.2 
 
 468.8 
 
 148.6 
 
 594.3 
 
 .55 
 
 .60 
 
 66.7 
 
 266.9 
 
 90.9 
 
 363.4 
 
 118.7 
 
 474.8 
 
 150.2 
 
 600.9 
 
 .60 
 
 .65 
 
 67.8 
 
 271.4 
 
 92.1 
 
 808. 6 
 
 120.2 
 
 480.7 
 
 151.9 
 
 607.6 
 
 .65 
 
 .70 
 
 69.0 
 
 275.9 
 
 93.5 
 
 3739 
 
 121.7 
 
 486.7 
 
 153.6 
 
 614.4 
 
 .70 
 
 .75 
 
 70.1 
 
 280.4 
 
 94.8 
 
 379.2 
 
 123.2 
 
 492.7 
 
 155.3 
 
 621.1 
 
 .75 
 
 .80 
 
 71.8 
 
 285.0 
 
 96.1 
 
 384.5 
 
 124.7 
 
 498.8 
 
 157.0 
 
 628.0 
 
 .80 
 
 .85 
 
 72.4 
 
 289.6 
 
 97.5 
 
 389.9 
 
 126.2 
 
 504.9 
 
 158.7 
 
 634.8 
 
 .85 
 
 .90 
 
 73.6 
 
 294.8 
 
 98.8 
 
 395.3 
 
 127.8 
 
 511.1 
 
 160.4 
 
 641.7 
 
 .90 
 
 .95 
 
 74.7 
 
 299.0 
 
 100.2 
 
 400.7 
 
 129.3 
 
 517.2 |i 162.1 
 
 648.6 
 
 .95 
 
 
 9 
 
 feet. 
 
 10 
 
 feet. 
 
 11 
 
 feet. 
 
 12 
 
 feet. 
 
 1 
 
 .00 
 
 1639 
 
 655.6 
 
 200.6 
 
 802.5 
 
 241.1 
 
 964.2 
 
 2852 
 
 1140.7 
 
 .OO 
 
 .05 
 
 165.6 
 
 662.6 
 
 202.5 
 
 810.2 
 
 243.2 
 
 972.7 
 
 287.5 
 
 1150.0 
 
 .05 
 
 .10 
 
 167.4 
 
 669.7 
 
 204.5 
 
 818.0 
 
 245.8 
 
 981.2 
 
 2898 
 
 1159.2 
 
 .10 
 
 .15 
 
 169.2 
 
 676.7 
 
 206.4 
 
 825.8 
 
 247.4 
 
 989.8 
 
 292.1 
 
 1168.5 
 
 .15 
 
 .20 
 
 170.9 
 
 6S3.8 
 
 208.4 
 
 883.6 
 
 249.6 
 
 998.3 
 
 294.5 
 
 1177.8 
 
 .20 
 
 .25 
 
 172.7 
 
 690.9 
 
 210.4 
 
 841.5 
 
 251.7 
 
 1006.7 
 
 296.8 
 
 1187.3 
 
 .25 
 
 .30 
 
 174.5 
 
 698.1 
 
 2124 
 
 849.4 
 
 253.9 
 
 1015.6 
 
 299.2 
 
 1196.7 
 
 .30 
 
 .85 
 
 176.8 
 
 705.8 
 
 214.3 
 
 857.4 
 
 256.1 
 
 1024.8 
 
 801.5 
 
 1206.1 
 
 .85 
 
 .40 
 
 178.1 
 
 712.5 
 
 216.3 
 
 865.4 
 
 258.3 
 
 1033.0 
 
 803.9 
 
 1215.5 
 
 .40 
 
 .45 
 
 180.0 
 
 719.9 
 
 218.3 
 
 873.4 
 
 260.4 
 
 1041.8 
 
 806.2 
 
 1225.0 
 
 .45 
 
 .50 
 
 181.8 
 
 727.2 
 
 220.4 
 
 881.5 
 
 262.7 
 
 1050.6 
 
 308.6 
 
 1284.6 
 
 .50 
 
 .55 
 
 188.6 
 
 734.5 
 
 222.4 
 
 889. 6 
 
 264.9 
 
 1059.5 
 
 811.0 
 
 1244.2 
 
 .55 
 
 .60 
 
 185.5 
 
 741.9 
 
 224.4 
 
 897.7 
 
 267.1 
 
 1068.4 
 
 818.4 
 
 1253.8 
 
 .60 
 
 .65 
 
 187.3 
 
 749.4 
 
 226.5 
 
 905.9 
 
 269.3 
 
 1077.3 
 
 815.8 
 
 1263.4 
 
 .65 
 
 .70 
 
 189.2 
 
 756.8 
 
 228.5 
 
 914.1 
 
 271.6 
 
 1086.2 
 
 318.3 
 
 1273.1 
 
 .70 
 
 .75 
 
 191.1 
 
 764.4 
 
 230.6 
 
 922.4 
 
 278.8 
 
 1095.2 
 
 820.7 
 
 1282.9 
 
 .75 
 
 .80 
 
 193.0 
 
 771.9 
 
 232.7 
 
 930.7 
 
 276.1 
 
 1104.2 
 
 823.2 
 
 1292.6 
 
 .80 
 
 .85 
 
 194.9 
 
 779.5 
 
 234.7 
 
 939.0 
 
 278.3 
 
 1113.3 
 
 825.6 
 
 1302.5 
 
 .85 
 
 .90 
 
 196.8 
 
 787.1 
 
 236.8 
 
 947.4 
 
 280. 6 
 
 1122.4 
 
 328.1 
 
 1312.3 
 
 .90 
 
 .95 
 
 198.7 
 
 794.8 
 
 238.9 955.8 
 
 282.9 
 
 1131.6 
 
 330.5 
 
 1322.2 
 
 .95 
 

 
 EMBANKING LANDS FEOM EIVEE-FLOODS. 
 
 155 
 
 TABLE I. (Continued.} 
 5 feet wide an top and 6 feet wide at base for every foot high. 
 
 Decimals of 
 a foot. 
 
 End 
 areas. 
 
 4 times 
 middle 
 area. 
 
 End 
 
 areas. ~ 
 
 4 times 
 middle 
 area: 
 
 End 
 areas. 
 
 4 times 
 middle 
 area. 
 
 End 
 areas. 
 
 4 times 
 middle 
 area. 
 
 Decimals of 
 a foot. 
 
 
 13 
 
 feet. 
 
 14 
 
 feet. 
 
 15 
 
 feet. 
 
 16 
 
 feet. 
 
 
 .00 
 
 333.0 
 
 1332.1 
 
 384.6 
 
 1533.3 
 
 439.8 
 
 1759.3 
 
 498.8 
 
 1995.1 
 
 .00 
 
 .05 
 
 835.5 
 
 1342.1 
 
 387.2 
 
 1549.0 
 
 442.7 
 
 1770.8 
 
 501.8 
 
 2007.2 
 
 .05 
 
 .10 
 
 3380 
 
 1352.0 
 
 889.9 
 
 15597 
 
 445.5 
 
 1782.2 
 
 504.9 
 
 2019.4 
 
 .10 
 
 .15 
 
 3405 
 
 13(5-2. 1 
 
 392.6 
 
 1570.5 
 
 4484 
 
 1793.7 
 
 507.9 
 
 2031.7 
 
 .15 
 
 .20 
 
 3430 
 
 1372.2 
 
 395.3 
 
 15813 
 
 451.3 
 
 1805.2 
 
 511.0 
 
 2044.0 
 
 .20 
 
 .25 
 
 345.6 
 
 1382 3 
 
 ! 398.0 
 
 1592.2 
 
 454.2 
 
 1816.8 
 
 514.1 
 
 2056.4 
 
 .25 
 
 .30 
 
 348.1 
 
 1392.4 
 
 400.8 
 
 1608.0 
 
 457.1 
 
 1828.4 
 
 517.2 
 
 2068.7 
 
 .30 
 
 .35 
 
 350.6 
 
 1402.6 
 
 403.5 
 
 1613.9 
 
 460.0 
 
 1840.1 
 
 520.3 
 
 2081.1 
 
 .85 
 
 .40 
 
 353.2 
 
 1412.8 
 
 406.2 
 
 1624.9 
 
 462.9 
 
 1851.8 
 
 5234 
 
 2093.5 
 
 ,4O 
 
 .45 
 
 355.8 
 
 1423.1 
 
 4090 
 
 1635.9 
 
 465.9 
 
 1863.6 
 
 526.5 
 
 2106.0 
 
 .45 
 
 .50 
 
 358.3 
 
 14:33 3 
 
 411.7 
 
 1646.9 
 
 468.8 
 
 1875.3 
 
 529.6 
 
 2118.5 
 
 .50 
 
 .55 
 
 360.9 
 
 1443.7 
 
 414.5 
 
 1658.0 
 
 471.7 
 
 1887.0 
 
 532.7 
 
 2131.0 
 
 .65 
 
 .60 
 
 3635 
 
 1454.0 
 
 417.3 
 
 1669.1 
 
 474.7 
 
 1898.7 
 
 535.9 
 
 2143.6 
 
 .60 
 
 .65 
 
 866.0 
 
 1464.0 
 
 420.1 
 
 16S0.3 
 
 477.7 
 
 1910.7 
 
 539.1 
 
 2156.3 
 
 .65 
 
 .70 
 
 368.7 
 
 1474.9 
 
 4229 
 
 1691.4 
 
 480.7 
 
 1922 8 
 
 542.2 
 
 2168.9 
 
 .70 
 
 .75 
 
 371.3 
 
 14S5.4 
 
 425.6 
 
 1702.6 
 
 4S3.7 
 
 1934.7 
 
 545.4 
 
 2181.7 
 
 .75 
 
 .SO 
 
 374.0 
 
 1495.8 
 
 428.5 
 
 1713.9 
 
 486.7 
 
 1946.6 
 
 548.6 
 
 2194.4 
 
 .80 
 
 .85 
 
 376.6 
 
 1506.4 
 
 431.3 
 
 1725.2 
 
 489.7 
 
 1958.7 
 
 551.7 
 
 2207.0 
 
 .85 
 
 .90 
 
 379.3 
 
 1517.0 
 
 434.1 
 
 1735.6 
 
 492.7 
 
 1970.8 
 
 554.9 
 
 2219.6 
 
 .90 
 
 .95 
 
 381.9 
 
 1527.6 
 
 436.9 
 
 1747.8 
 
 495.7 
 
 1982.9 
 
 558.1 
 
 2232.6 
 
 .95 
 
 
 17 
 
 feet. 
 
 18 
 
 feet. 
 
 19 
 
 feet. 
 
 20 
 
 feet. 
 
 
 .00 
 
 561.4 
 
 2245.7 
 
 6278 
 
 2511.1 
 
 697.8 
 
 2791.4 
 
 7716 
 
 3086.4 
 
 .OO 
 
 .05 
 
 564.6 
 
 2258.6 
 
 6312 
 
 2524.8 
 
 701.4 
 
 2805.8 
 
 775.4 
 
 3101.6 
 
 .05 
 
 .10 
 
 567.9 
 
 2271.6 
 
 634.6 
 
 2538.5 
 
 705.1 
 
 2820.2 
 
 779.2 
 
 8116.7 
 
 .10 
 
 .15 
 
 571.1 
 
 22846 
 
 638.0 
 
 2552.2 
 
 708.7 
 
 2884.7 
 
 783.0 
 
 8131.9 
 
 .15 
 
 .20 
 
 574.4 
 
 2297.6 
 
 641.5 
 
 2566.0 
 
 712.8 
 
 2849.2 
 
 786.8 
 
 3147.2 
 
 .20 
 
 .25 
 
 577.7 
 
 2310.7 
 
 644.9 
 
 2579.8 
 
 715.9 
 
 2863.7 
 
 790.6 
 
 8162.5 
 
 .25 
 
 .30 
 
 580.9 
 
 2323.8 
 
 648.4 
 
 2593.6 
 
 719.6 
 
 2878.3 
 
 794.5 
 
 31779 
 
 .30 
 
 .35 
 
 584.2 
 
 2336.9 
 
 651.9 
 
 2607.5 
 
 723.2 
 
 2898.0 
 
 798.3 
 
 8193.2 
 
 .35 
 
 .40 
 
 587.5 
 
 2350.1 
 
 655.4 
 
 2621.4 
 
 726.9 
 
 2907.6 
 
 802.2 
 
 8208.6 
 
 .40 
 
 .45 
 
 590.8 
 
 2363.3 
 
 6588 
 
 2635.4 
 
 780.6 
 
 29223 
 
 806.0 
 
 3224.0 
 
 .45 
 
 .50 
 
 594.1 
 
 2376.6 
 
 662.3 
 
 2649.4 
 
 734.3 
 
 2937.0 
 
 8099 
 
 82395 
 
 .SO 
 
 .55 
 
 597.5 
 
 2389.9 
 
 665.9 
 
 2663.5 
 
 737.9 
 
 2951.8 
 
 813.8 
 
 3255.1 
 
 .55 
 
 .60 
 
 600.8 
 
 2403.2 
 
 669.4 
 
 2677.5 
 
 741.7 
 
 2966.6 
 
 817.6 
 
 8270.6 
 
 .60 
 
 .65 
 
 604.1 
 
 24166 
 
 672.9 
 
 2691.6 
 
 745.4 
 
 2981.5 
 
 821.5 
 
 3286.2 
 
 .65 
 
 .70 
 
 607.5 
 
 2429.9 
 
 676.4 
 
 2705.7 
 
 749.1 
 
 2996.3 
 
 825.4 
 
 8301.8 
 
 .70 
 
 .75 
 
 610.8 
 
 2443.3 
 
 680.0 
 
 2719.9 
 
 752.8 
 
 3011.2 
 
 829.4 
 
 8317.5 
 
 .75 
 
 .80 
 
 614.2 
 
 2-156.8 
 
 683 5 
 
 2784.1 
 
 756.6 
 
 80262 
 
 833.3 
 
 88331 
 
 .SO 
 
 .85 
 
 6176 
 
 2470.3 
 
 687.1 
 
 2748.4 
 
 760.3 
 
 8041.1 
 
 837.2 
 
 3848.9 
 
 .85 
 
 .90 
 
 621.0 
 
 2483.9 
 
 690.7 
 
 2762.7 
 
 764.1 
 
 3056.2 
 
 841.2 
 
 8364.6 
 
 .90 
 
 .95 
 
 624.4 
 
 2497.5 
 
 694.2 
 
 2777.0 
 
 767.8 
 
 3071.3 
 
 845.1 
 
 33S0.4 
 
 .95 
 
 21 
 
 feet. 
 
 22 
 
 feet. 
 
 23 
 
 feet. 
 
 24 
 
 feet. 
 
 
 .OO 1 849.1 
 
 3396.4 
 
 930.2 
 
 3721.0 
 
 10151 
 
 4060.5 
 
 1103.7 
 
 4414.8 
 
 .OO 
 
 .05 
 
 853.0 
 
 34122 
 
 934.4 
 
 3737.7 
 
 1019.5 
 
 4077.9 
 
 1108.2 
 
 4482.9 
 
 .05 
 
 .10 
 
 857.0 
 
 8428.1 
 
 938.6 
 
 3754.3 
 
 1023.8 
 
 4095.3 
 
 1112.8 
 
 4451.1 
 
 .10 
 
 .15 
 
 861.0 
 
 8444.0 
 
 942.7 
 
 3771.0 
 
 1028.2 
 
 4112.7 
 
 1117.3 
 
 4469.3 
 
 .15 
 
 .20 
 
 865.0 
 
 3460.0 
 
 946.9 
 
 3787.7 
 
 1032.5 
 
 4130.2 
 
 1121.9 
 
 4487.5 
 
 .20 
 
 .25 
 
 869.0 
 
 34761 
 
 951.1 
 
 3804.5 
 
 1036.9 
 
 4147.7 
 
 1126.4 
 
 4505.8 
 
 25 
 
 .30 
 
 873.0 
 
 3492.2 
 
 955.3 
 
 3821.3 
 
 1041.8 
 
 4165.2 
 
 1131.0 
 
 4524.0 
 
 ,3O 
 
 .85 
 
 877.1 
 
 85083 
 
 959.5 
 
 3838.1 
 
 1045.7 
 
 4182.8 
 
 1135.6 
 
 4542.3 
 
 .85 
 
 .40 
 
 | 881.1 
 
 3524.4 
 
 963.8 
 
 8855.0 
 
 1050.1 
 
 4200.4 
 
 11402 
 
 4560.7 
 
 .40 
 
 .45 
 
 885.1 
 
 8540.6 
 
 9680 
 
 3872.0 
 
 1054.5 
 
 4218.1 
 
 11448 
 
 4579.1 
 
 .45 
 
 .50 
 
 889.2 
 
 3556.8 
 
 972.2 
 
 8888.9 
 
 1059.0 
 
 4235.8 
 
 1149.4 
 
 4597.5 
 
 .50 
 
 .55 
 
 893.2 
 
 3573.0 
 
 976.5 
 
 3905.9 
 
 1063.4 
 
 4253.6 1154.0 
 
 4616.0 
 
 .55 
 
 .60 
 
 897.3 
 
 35S9.3 
 
 980.7 
 
 8922.9 
 
 1067.8 
 
 4271.3 
 
 1158 6 
 
 4634.5 
 
 .60 
 
 .65 i 
 
 901.2 
 
 8605.7 
 
 9850 
 
 3910.0 
 
 1072.3 
 
 4289.1 
 
 1163.3 
 
 4653.1 
 
 .65 
 
 .70 
 
 905.5 
 
 8622.1 
 
 989.3 
 
 3957.1 
 
 1076.7 
 
 4306.9 
 
 1167.9 
 
 4671.7 
 
 .70 
 
 .75 
 
 909.6 
 
 3638.5 
 
 993.6 
 
 8974.3 
 
 10812 
 
 4324.8 
 
 1172.6 
 
 4690.3 
 
 .75 
 
 .80 
 
 913.7 
 
 3654.9 
 
 1 997.9 
 
 3991.4 
 
 1085.7 
 
 4342.7 
 
 1177.2 
 
 4708.9 
 
 .SO 
 
 .85 
 
 917.8 
 
 3671.4 
 
 1002.1 
 
 4008.6 
 
 1090.2 
 
 4360.7 
 
 1181.9 
 
 4727.7 
 
 .85 
 
 .90 
 
 922.0 
 
 8687.9 
 
 1006.5 
 
 4025.9 
 
 10947 
 
 4378.7 
 
 1186.6 
 
 4746.4 
 
 .90 
 
 .95 
 
 926.1 
 
 3704.4 
 
 1010.8 
 
 4043.2 
 
 1099.2 
 
 4396.8 
 
 11913 
 
 4765.1 
 
 .95 
 
156 
 
 PRINCIPLES AND PRACTICE OF 
 
 TABLE IL 
 
 Table of Cubic Yards corresponding to a cross section 3 feet wide 
 
 Decimals 
 of a foot. 
 
 End 
 
 areas. 
 
 4 times 
 middle 
 
 End 
 areas. 
 
 4 times 
 middle 
 
 End 
 areas. 
 
 4 times 
 middle 
 
 End 
 areas. 
 
 4 times 
 middle 
 
 Decimals 
 of a foot. 
 
 
 
 area. 
 
 
 area. 
 
 
 area. 
 
 
 area. 
 
 
 
 1 
 
 foot. 
 
 2 
 
 feet. 
 
 3 
 
 feet. 
 
 4 
 
 feet. 
 
 
 .00 
 
 2.8 
 
 11.1 
 
 9.3 
 
 87.0 
 
 19.4 
 
 77.8 
 
 88.3 
 
 133.8 
 
 .00 
 
 .05 
 
 8.0 
 
 12.1 
 
 9.7 
 
 88.7 
 
 20.1 
 
 80.3 
 
 84.1 
 
 136.5 
 
 .05 
 
 .10 
 
 8.3 
 
 13.0 
 
 10.1 
 
 40.4 
 
 20.7 
 
 82.7 
 
 84.9 
 
 139.7 
 
 .to 
 
 .15 
 
 8.5 
 
 14.0 
 
 10.5 
 
 42.2 
 
 21.3 
 
 85.2 
 
 85.7 
 
 142.9 
 
 .15 
 
 .20 
 
 8.8 
 
 15.1 
 
 11.0 
 
 44.0 
 
 21.9 
 
 87.7 
 
 86.6 
 
 146.2 
 
 .20 
 
 .25 
 
 4.0 
 
 16.2 
 
 11.4 
 
 45.8 
 
 22.7 
 
 90.8 
 
 37.3 
 
 1493 
 
 .25 
 
 .30 
 
 4.8 
 
 17.3 
 
 11.9 
 
 47.7 
 
 23.2 
 
 93.8 
 
 88.2 
 
 152.9 
 
 .30 
 
 .85 
 
 4.6 
 
 18.5 
 
 12.4 
 
 49.7 
 
 24.0 
 
 96.0 
 
 39.1 
 
 156.3 
 
 .85 
 
 .40 
 
 4.9 
 
 19.7 
 
 12.9 
 
 51.6 
 
 24.6 
 
 98.2 
 
 39.9 
 
 159.7 
 
 .40 
 
 .45 
 
 5.2 
 
 21.0 
 
 13.4 
 
 53.5 
 
 25.2 
 
 100.9 
 
 40.8 
 
 163.2 
 
 .45 
 
 .50 
 
 6.6 
 
 22.2 
 
 13.9 
 
 55.5 
 
 25.9 
 
 103.7 
 
 41.7 
 
 166.7 
 
 .50 
 
 .55 
 
 5.9 
 
 23.5 
 
 14.4 
 
 57.6 
 
 26.6 
 
 106.5 
 
 42.6 
 
 170.3 
 
 .55 
 
 .60 
 
 62 
 
 24.9 
 
 14.9 
 
 59.7 
 
 27.3 
 
 109.3 
 
 43.4 
 
 1738 
 
 .60 
 
 .65 
 
 6.6 
 
 26.8 
 
 15.4 
 
 61.8 
 
 28.0 
 
 112.2 
 
 44.3 
 
 177.4 
 
 .65 
 
 .70 
 
 6.9 
 
 27.7 
 
 16.0 
 
 64.0 
 
 2S.8 
 
 115.1 
 
 45.3 
 
 181.0 
 
 .70 
 
 .75 
 
 7.8 
 
 29.2 
 
 16.5 
 
 66.2 
 
 29.5 
 
 118.0 
 
 46.2 
 
 1S4.9 
 
 .75 
 
 .80 
 
 7.7 
 
 80.7 
 
 17.1 
 
 6S.4 
 
 80.3 
 
 121.0 
 
 47.1 
 
 188.4 
 
 .80 
 
 .85 
 
 8.1 
 
 82.3 
 
 17.7 
 
 70.7 
 
 31.0 
 
 124.1 
 
 48.0 
 
 192.2 
 
 .85 
 
 .90 
 
 8.4 
 
 33.8 
 
 18.3 
 
 73.0 
 
 81.8 
 
 127.1 
 
 49.0 
 
 196.0 
 
 .90 
 
 .95 
 
 8.8 
 
 85.4 
 
 18.8 
 
 75.4 
 
 82.5 
 
 . 130.2 
 
 50.0 
 
 199.9 
 
 .95 
 
 
 5 
 
 feet. 
 
 6 
 
 feet. 
 
 7 
 
 feet 
 
 8 
 
 feet. 
 
 
 .00 
 
 50.9 
 
 203.7 
 
 72.2 
 
 288.9 
 
 97.2 
 
 388.9 
 
 125.9 
 
 503.7 
 
 .00 
 
 .05 
 
 51.9 
 
 207.6 
 
 73.4 
 
 293.6 
 
 98.6 
 
 894.3 
 
 127.5 
 
 509.9 
 
 .05 
 
 .10 
 
 52.9 
 
 2)1.6 
 
 74.6 
 
 298.2 
 
 99.9 
 
 899.7 
 
 129.0 
 
 516.0 
 
 .10 
 
 .15 
 
 53.9 
 
 215.6 
 
 75.7 
 
 803.0 
 
 101.8 
 
 405.2 
 
 130.5 
 
 522.2 
 
 .15 
 
 .20 
 
 54.9 
 
 219.6 
 
 76.9 
 
 807.7 
 
 102.7 
 
 410.7 
 
 132.1 
 
 5284 
 
 .20 
 
 .25 
 
 55.9 
 
 223.6 
 
 78.1 
 
 312.5 
 
 104.1 
 
 416.3 
 
 133.7 
 
 534.7 
 
 .25 
 
 .30 
 
 56.9 
 
 227.7 
 
 79.3 
 
 817.3 
 
 105.4 
 
 421.8 
 
 135.3 
 
 541.0 
 
 .30 
 
 .85 
 
 53.0 
 
 281.9 
 
 80.5 
 
 822.2 
 
 106.8 
 
 427.4 
 
 K6.8 
 
 547.4 
 
 .35 
 
 .40 
 
 59.0 
 
 236.0 
 
 81.8 
 
 827.1 
 
 108.8 
 
 433.0 
 
 138.4 
 
 553.8 
 
 .40 
 
 .45 
 
 60.0 
 
 240.2 
 
 83.0 
 
 832.0 
 
 109.7 
 
 438.7 
 
 140.1 
 
 560.8 
 
 .45 
 
 .50 
 
 61.1 
 
 244.4 
 
 84.8 
 
 837.0 
 
 111.1 
 
 444.4 
 
 141.7 
 
 566.7 
 
 .50 
 
 .55 
 
 62.2 
 
 248.7 
 
 85.5 
 
 342.1 
 
 112.5 
 
 450.2 
 
 143.3 
 
 573.2 
 
 .55 
 
 .60 
 
 63.8 
 
 253.0 
 
 86.8 
 
 847.1 
 
 114.0 
 
 456.0 
 
 144.9 
 
 579.7 
 
 .60 
 
 .65 
 
 64.3 
 
 257.4 
 
 88.0 
 
 352.2 
 
 115.4 
 
 461.8 
 
 146.6 
 
 586.3 
 
 .65 
 
 .70 
 
 65.4 
 
 261.8 
 
 89.3 
 
 357.3 
 
 116.9 
 
 467.7 
 
 148.2 
 
 592.9 
 
 .70 
 
 .75 
 
 66.6 
 
 266.3 
 
 90.6 
 
 862.5 
 
 118.4 
 
 473.7 
 
 149.9 
 
 599.6 
 
 .75 
 
 .80 
 
 67.7 
 
 270.7 
 
 91.9 
 
 867.7 
 
 119.9 
 
 479.6 
 
 151.6 
 
 606.3 
 
 .80 
 
 .85 
 
 68.8 
 
 275.4 
 
 93.2 
 
 873.0 
 
 121.4 
 
 485.6 
 
 153.2 
 
 613.0 
 
 .85 
 
 .90 
 
 69.9 
 
 279.7 
 
 94.6 
 
 878.2 
 
 122.9 
 
 491.6 
 
 154.9 
 
 619.7 
 
 .90 
 
 .95 
 
 71.1 
 
 284.3 
 
 95.9 
 
 883.6 
 
 124.4 
 
 497.7 
 
 156.6 
 
 626.5 
 
 .95 
 
 
 9 
 
 feet 
 
 10 
 
 feet 
 
 11 
 
 feet. 
 
 12 
 
 feet 
 
 
 .00 
 
 158.8 
 
 6338 
 
 194.4 
 
 777.8 
 
 234.3 
 
 937.0 
 
 277.8 
 
 lill.l 
 
 .00 
 
 .05 
 
 160.0 
 
 640.2 
 
 196.3 
 
 785.4 
 
 236.3 
 
 945.4 
 
 280.5 
 
 1122.2 
 
 .05 
 
 .10 
 
 161.8 
 
 647.1 
 
 198.3 
 
 793.0 
 
 23S.4 
 
 953.8 
 
 2S2.8 
 
 1129.3 
 
 .10 
 
 .15 
 
 163.5 
 
 654.0 
 
 200.2 
 
 800.7 
 
 240.6 
 
 962.3 
 
 2S4.6 
 
 1188.5 
 
 .15 
 
 .20 
 
 165.3 
 
 661.0 
 
 202.1 
 
 808.4 
 
 242.7 
 
 970.7 
 
 286.9 
 
 1147.7 
 
 .20 
 
 .25 
 
 167.0 
 
 668.1 
 
 204.1 
 
 816.4 
 
 244.8 
 
 979.2 
 
 2S9.2 
 
 1156.9 
 
 .25 
 
 .30 
 
 168.8 
 
 675.1 
 
 206.0 
 
 824.0 
 
 246.9 
 
 9S7.7 
 
 291.6 
 
 1166.2 
 
 .30 
 
 .85 
 
 170.5 
 
 682.2 
 
 207.9 
 
 831.8 
 
 249.1 
 
 996.3 
 
 293.9 
 
 1175.6 
 
 .35 
 
 .40 
 
 172.3 
 
 689.8 
 
 209.9 
 
 839.7 
 
 251.2 
 
 1004.9 
 
 296.2 
 
 1184.9 
 
 .40 
 
 .45 
 
 174.1 
 
 696.5 
 
 211.9 
 
 847.7 
 
 253.4 
 
 1013.6 
 
 298.6 
 
 1194.3 
 
 .45 
 
 .50 
 
 175.9 
 
 703.7 
 
 213.9 
 
 855.6 
 
 255.6 
 
 1022.2 
 
 800.9 
 
 1203.7 
 
 .50 
 
 .55 
 
 177.7 
 
 711.0 
 
 215.9 
 
 863.6 
 
 257.7 
 
 1030.9 
 
 303.8 
 
 1213.2 
 
 .55 
 
 .60 
 
 179.6 
 
 718.2 
 
 217.9 
 
 871.6 
 
 259.9 
 
 1039.7 
 
 805.7 
 
 1222.7 
 
 .60 
 
 .65 
 
 181.4 
 
 725.6 
 
 219.9 
 
 879.7 
 
 262.1 
 
 1048.5 
 
 808.1 
 
 1232.8 
 
 .65 
 
 .70 
 
 183.2 
 
 732.9 
 
 221.9 
 
 887.7 
 
 264.8 
 
 1057.3 
 
 810.5 
 
 1242.0 
 
 .70 
 
 .75 
 
 185.1 
 
 740.3 
 
 224.0 
 
 895.9 
 
 266.5 
 
 1066.2 
 
 812.5 
 
 1251.5 
 
 .75 
 
 .SO 
 
 186.9 
 
 747.7 
 
 226.0 
 
 904.0 
 
 268.8 
 
 1075.1 
 
 815.3 
 
 1261.0 
 
 .80 
 
 .85 
 
 188.8 
 
 755.2 
 
 228.0 
 
 912.2 
 
 271.0 
 
 1084.0 
 
 817.6 
 
 1270.6 
 
 .85 
 
 .90 
 
 190.7 
 
 762.7 
 
 230.1 
 
 920.4 
 
 273.3 
 
 1093.0 
 
 820.1 
 
 1280.2 
 
 .90 
 
 .95 
 
 192.6 
 
 770.3 
 
 232.2 
 
 928.7 
 
 275.5 
 
 1102.0 
 
 322.5 
 
 1290.1 
 
 .95 
 
EMBANKING LANDS FKOM RIVEB-FLOODS. 
 
 157 
 
 TABLE H. (Continued.) 
 on top and 6 feet wide at base for every foot high. 
 
 Decimals of 
 a foot. 
 
 End 
 
 areas. 
 
 4 times 
 middle 
 area. 
 
 1 
 End 
 areas. 
 
 4 times 
 , middle 
 area. 
 
 End 
 areas. 
 
 4 times 
 middle 
 area. 
 
 End 
 areas. 
 
 4 times 
 middle 
 area. 
 
 Decimals of 
 a foot. 
 
 
 13 
 
 feet. 
 
 14 
 
 feet. 
 
 15 
 
 feet. 
 
 ~"l6 
 
 feet. 
 
 
 .00 
 
 825.0 
 
 1300.0 
 
 875.9 
 
 1503.7 
 
 430.6 
 
 1722.2 
 
 488.9 
 
 1955.6 
 
 .OO 
 
 .05 
 
 827.0 
 
 1809.9 
 
 878.6 
 
 1514.8 
 
 438.4 
 
 1788.6 
 
 491.9 
 
 1967.7 
 
 .05 
 
 .10 
 
 329.9 
 
 1319.7 
 
 381.2 
 
 1524.9 
 
 436.2 
 
 1744.9 
 
 494.9 
 
 1979.7 
 
 .10 
 
 .15 
 
 332.4 
 
 1829.7 
 
 383.9 
 
 1535.6 
 
 489.1 
 
 1756.8 
 
 498.0 
 
 1991.9 
 
 .15 
 
 .20 
 
 334.9 
 
 1339.6 
 
 386.6 
 
 1546.2 
 
 441.9 
 
 1767.7 
 
 501.0 
 
 2004.0 
 
 .20 
 
 .25 
 
 837.4 
 
 1349.6 
 
 889.2 
 
 1556.9 
 
 444.8 
 
 1779.2 
 
 504.0 
 
 2016.2 
 
 .25 
 
 .30 
 
 839.9 
 
 1:359.6 
 
 391.9 
 
 1567.7 
 
 447.7 
 
 1790.7 
 
 507.1 
 
 2028.4 
 
 .30 
 
 .35 
 
 842.4 
 
 1369.7 
 
 394.6 
 
 1578.5 
 
 450.5 
 
 1802.2 
 
 510.2 
 
 2040.7 
 
 1.85 
 
 .40 
 
 344.9 
 
 1879.7 
 
 1 897.3 
 
 1589.8 
 
 453.4 
 
 1818.8 
 
 513.8 
 
 2053.0 
 
 .40 
 
 .45 
 
 847.5 
 
 13S9.9 
 
 1 400.0 
 
 1600.2 
 
 456.3 
 
 1825.4 
 
 516.8 
 
 2065.4 
 
 .45 
 
 .50 
 
 3500 
 
 1400.0 
 
 402.8 
 
 1611.1 
 
 459.3 
 
 1837.0 
 
 519.4 
 
 2077.8 
 
 .50 
 
 .55 
 
 352.5 
 
 1410.2 
 
 405.5 
 
 1622.1 
 
 462.2 
 
 1848.7 
 
 522.6 
 
 2090.3 
 
 '.55 
 
 .60 
 
 355.1 
 
 1420.4 
 
 40S.3 
 
 1633.0 
 
 465.1 
 
 1860.4 
 
 1 525.7 
 
 2102.7 
 
 .60 
 
 .65 
 
 857.7 
 
 1430.7 
 
 411.0 
 
 1644.1 
 
 468.0 
 
 1872.2 
 
 528.8 
 
 2115.2 
 
 .65 
 
 .70 
 
 3603 
 
 1441.0 
 
 413.8 
 
 1655.1 
 
 471.0 
 
 1884.0 
 
 531.9 
 
 2127.7 
 
 .70 
 
 .75 
 
 362.8 
 
 1451.4 
 
 416.5 
 
 1666.2 
 
 473.9 
 
 1895.8 
 
 535.1 
 
 2140.8 
 
 .75 
 
 .80 
 
 365.4 
 
 1461.8 
 
 419.3 
 
 1677.3 
 
 476.9 
 
 1907.7 
 
 538.2 
 
 2152.9 
 
 .80 
 
 .85 
 
 868.1 
 
 1472.3 
 
 422.1 
 
 1688.5 
 
 479.9 
 
 1919.7 
 
 541.4 
 
 2165.6 
 
 .85 
 
 .90 
 
 370.7 
 
 1482.7 
 
 424.9 
 
 1699.7 
 
 482.9 
 
 1931.6 
 
 544.6 
 
 2178.2 
 
 .90 
 
 .95 
 
 373.3 
 
 1493.2 
 
 427.7 
 
 1711.0 
 
 485.9 
 
 1943.6 
 
 547.7 
 
 2191.0 
 
 .95 
 
 
 17 
 
 feet. 
 
 18 
 
 feet. 
 
 19 
 
 feet. 
 
 20 
 
 feet, 
 
 
 .00 
 
 550.9 
 
 2203.7 
 
 616.7 
 
 2466.7 
 
 6S6.1 
 
 2744.4 
 
 759.8 
 
 3037.0 
 
 .OO 
 
 .05 
 
 554.1 
 
 2216.5 
 
 620.1 
 
 2480.3 
 
 689.7 
 
 2758.7 
 
 763.0 
 
 8052.0 
 
 .05 
 
 .10 
 
 557.3 
 
 2229.3 
 
 623.4 
 
 2493.8 
 
 693.3 
 
 2773.0 
 
 766.7 
 
 8067.0 
 
 .10 
 
 .15 
 
 560.5 
 
 2242.2 
 
 626.8 
 
 2507.4 
 
 696.8 
 
 2787.4 
 
 770.5 
 
 3082.2 
 
 .15 
 
 .20 
 
 563.8 
 
 2255.1 
 
 630.3 
 
 2521.0 
 
 700.4 
 
 2801.8 
 
 774.8 
 
 3097.3 
 
 .20 
 
 .25 
 
 5670 
 
 2268.1 
 
 633.7 
 
 2534.7 
 
 704.1 
 
 2816.3 
 
 778.1 
 
 3112.5 
 
 .25 
 
 .30 
 
 570.3 
 
 2281.0 
 
 637.1 
 
 2548.4 
 
 707.7 
 
 2830.7 
 
 781.9 
 
 8127.7 
 
 .30 
 
 .85 
 
 573.5 
 
 2294.0 ' 
 
 640.5 
 
 2562.2 
 
 711.3 
 
 2845.2 
 
 785.7 
 
 8143.0 
 
 .85 
 
 .40 
 
 5768 
 
 2307.1 
 
 644.0 
 
 2576.0 
 
 714.9 
 
 2859.7 
 
 789.6 
 
 3158.2 
 
 .40 
 
 .45 
 
 580.0 
 
 2320.2 
 
 647.4 
 
 2589.8 
 
 718.6 
 
 2874.3 
 
 798.4 
 
 81786 
 
 .45 
 
 .50 
 
 583.8 
 
 2333 3 
 
 650.9 
 
 2603.7 
 
 7222 
 
 2888.9 
 
 797.2 
 
 3188.9 
 
 .50 
 
 .55 
 
 586.6 
 
 2346.5 
 
 654.4 
 
 2617.7 
 
 725.9 
 
 2903.6 
 
 801.8 
 
 8204.3 
 
 .55 
 
 .60 
 
 589.9 
 
 2359.7 
 
 657.9 
 
 2631.6 
 
 729.6 
 
 2918.2 
 
 804.9 
 
 8219.7 
 
 .60 
 
 .65 
 
 593.2 
 
 2373.0 
 
 661.4 
 
 2645.6 
 
 733.2 
 
 2933.0 
 
 808.8 
 
 3235.2 
 
 .65 
 
 7O 
 
 596.6 
 
 2386.2 
 
 664.9 
 
 2659.6 
 
 736.9 
 
 2947.0 
 
 812.7 
 
 8250.7 
 
 .70 
 
 .75 
 
 5999 
 
 2399.6 
 
 668.4 
 
 2673.6 
 
 740.6 
 
 2962.5 
 
 816.6 
 
 3266.3 
 
 .75 
 
 .80 
 
 603.2 
 
 2412.9 
 
 671.9 
 
 2687.7 
 
 744.3 
 
 2977.3 
 
 820.4 
 
 8281.8 . 
 
 .80 
 
 .85 
 
 6066 
 
 2426.3 
 
 675.4 
 
 2701.8 
 
 748.0 
 
 2992.2 
 
 824.3 
 
 3297.4 
 
 .85 
 
 .90 
 
 609.9 
 
 2439.7 
 
 679.0 
 
 2716.0 
 
 751.8 
 
 3007.1 
 
 828.3 
 
 3313.0 
 
 .90 
 
 .95| 
 
 613.3 
 
 2453.2 
 
 682:5 
 
 2730.2 
 
 755.0 
 
 3022.1 
 
 832.2 
 
 3328.7 
 
 .95 
 
 
 21 
 
 feet. 
 
 22 
 
 feet. 
 
 23 
 
 feet. 
 
 24 
 
 feet. 
 
 
 .00 
 
 836.1 
 
 3344.4 
 
 916.7 
 
 3666.7 
 
 1000.9 
 
 4003.7 
 
 1088.9 
 
 4355.6 
 
 .OO 
 
 .05 
 
 840.0 
 
 8360.2 
 
 920.8 
 
 3683.2 
 
 1005.2 
 
 4021.0 
 
 1093.4 
 
 4873.6 
 
 .05 
 
 .10 
 
 844.0 
 
 3376.0 
 
 924.9 
 
 3699.7 
 
 1009.6 
 
 4038.2 
 
 1097.9 
 
 4391.1 
 
 .10 
 
 .15 
 
 848.0 
 
 3391.9 
 
 929.1 
 
 3716.3 
 
 1013.9 
 
 4055.6 
 
 1102.4 
 
 44097 
 
 .15 
 
 .20 
 
 851.9 
 
 3407.7 
 
 933.2 
 
 8732.9 
 
 1018.2 
 
 4072.9 
 
 1106.9 
 
 4427.7 
 
 .20 
 
 .25 
 
 855.9 
 
 3423.6 
 
 937.4 
 
 3749.6 
 
 1022.6 
 
 4090.3 
 
 1111.5 
 
 4445.9 
 
 .25 
 
 .30 
 
 859.9 
 
 3439.6 
 
 941.6 
 
 3766.2 
 
 1026.9 
 
 4107.7 
 
 1116.0 
 
 4464.0 
 
 .30 
 
 .85 
 
 863.9 
 
 3455.6 
 
 945.7 
 
 3783.0 
 
 1031.3 
 
 4125.2 
 
 1120.5 
 
 4482.2 
 
 .35 
 
 .40 
 
 867.9 
 
 3471.6 
 
 949.9 
 
 3799.7 
 
 1035.7 
 
 4142.7 
 
 1125.1 
 
 4500.4 
 
 .40 
 
 .45 
 
 871.9 
 
 8487.6 
 
 954.1 
 
 3S16.5 
 
 1040.1 
 
 4160.3 
 
 1129.7 
 
 4518.7 
 
 .45 
 
 .50 
 
 875.9 
 
 3503.7 
 
 958.3 
 
 8833.3 
 
 1044.4 
 
 4177.8 
 
 1134.3 
 
 4537.0 
 
 .50 
 
 .55 
 
 879.9 
 
 3519.8 
 
 962.5 
 
 3850.2 
 
 1048.8 
 
 4195.4 
 
 1138.8 
 
 4555.4 
 
 .55 
 
 .60 
 
 884.0 
 
 3536.0 
 
 966.8 
 
 3S6T.1 
 
 1053.3 
 
 4213.0 
 
 1143.4 
 
 4573.8 
 
 .60 
 
 .65 
 
 888.0 
 
 3552.2 
 
 971.0 
 
 3884.1 
 
 1057.7 
 
 4230.7 
 
 1148.1 
 
 4592.3 
 
 .65 
 
 .70 
 
 892.1 
 
 8568.4 
 
 975.3 
 
 3901.1 
 
 1062.1 
 
 4248.4 
 
 1152.7 
 
 4610.9 
 
 .70 
 
 .75 
 
 896.2 
 
 3584.7 
 
 979.5 
 
 8918.1 
 
 1066.5 
 
 4266.2 
 
 1157.3 
 
 4629.3 
 
 .75 
 
 .80 
 
 900.3 
 
 3601.0 
 
 983.8 
 
 3935.1 
 
 1071.0 
 
 4284.0 
 
 1161.9 
 
 4647.7 
 
 .80 
 
 .85 
 
 904.3 
 
 3617.4 
 
 9880 
 
 3952.2 
 
 1075.4 
 
 4301.8 
 
 1166.6 
 
 4666.3 
 
 .85 
 
 .90 
 
 908.4 
 
 8633.8 
 
 992.3 
 
 3969.3 
 
 1079.9 
 
 4319.7 
 
 1171.2 
 
 4684.9 
 
 .90 
 
 .95 
 
 912.6 
 
 3650.3 
 
 996.6 
 
 3986.5 
 
 1084.4 
 
 4337.7 
 
 1175.9 
 
 4703.6 
 
 .95 
 
158 
 
 PEINCIPLES AND PEACTICE OF 
 
 TABLE in. 
 
 Table of cubic yards corresponding to a cross section 3 feet wide 
 
 Decimals 
 of a foot. 
 
 End 
 areas. 
 
 4 times 
 middle 
 area. 
 
 End 
 areas. 
 
 4 times 
 middle 
 area. 
 
 End 
 areas. 
 
 4 times 
 middle 
 area. 
 
 End 
 areas. 
 
 4 times 
 middle 
 area. 
 
 Decimals of 
 a foot. 
 
 
 1 
 
 foot 
 
 2 
 
 feet. 
 
 3 
 
 feet. 
 
 4 
 
 feet. 
 
 
 .00 
 
 8.1 
 
 12.4 
 
 10.5 
 
 42.0 
 
 22.2 
 
 88.9 
 
 38.3 
 
 153.1 
 
 .00 
 
 .05 
 
 3.4 
 
 13.5 
 
 11.0 
 
 44.0 
 
 22.9 
 
 91.7- 
 
 39.2 
 
 156.8 
 
 .05 
 
 .10 
 
 3.6 
 
 14.5 
 
 11.5 
 
 45.9 
 
 23.6 
 
 94.5 
 
 40.1 
 
 160.5 
 
 .10 
 
 .15 
 
 3.9 
 
 15.7 
 
 12.0 
 
 48.0 
 
 24.4 
 
 97.5 
 
 41.1 
 
 164.3 
 
 .15 
 
 .20 
 
 4.2 
 
 16.9 
 
 12.5 
 
 50.0 
 
 25.1 
 
 100.4 
 
 42.0 
 
 16S.O 
 
 .20 
 
 .25 
 
 4.5 
 
 13.2 
 
 13.0 
 
 52.1 
 
 258 
 
 103.3 
 
 42.9 
 
 171.8 
 
 .25 
 
 .30 
 
 4.9 
 
 19.4 
 
 13.6 
 
 54.2 
 
 26.6 
 
 106.3 
 
 43.9 
 
 175.7 
 
 .30 
 
 .35 
 
 5.2 
 
 20.8 
 
 141 
 
 56.5 ! 
 
 27.3 
 
 109.4 
 
 44.9 
 
 179.7 
 
 .35 
 
 .40 
 
 5.5 
 
 22.1 
 
 14.7 
 
 58.7 i 
 
 28.1 
 
 112.5 
 
 45.9 
 
 183.6 
 
 .40 
 
 .45 
 
 5.9 
 
 23.6 
 
 15.2 
 
 61.0 
 
 28.9 
 
 115.7 
 
 46.9 
 
 187.7 
 
 .45 
 
 .50 
 
 63 
 
 25.0 
 
 15.8 
 
 63.3 
 
 29.7 
 
 118.8 
 
 47.9 
 
 191.7 
 
 .50 
 
 .55- 
 
 66 
 
 26.6 
 
 16.4 
 
 65.7 
 
 80.5 
 
 122.0 
 
 48.9 
 
 195.8 
 
 .55 
 
 .60 
 
 T.O 
 
 28.1 
 
 17.0 
 
 68.1 
 
 31.3 
 
 125-3 
 
 50.0 
 
 199.9 
 
 .60 
 
 .65 
 
 T.4 
 
 29.7 
 
 17.6 
 
 70.6 
 
 32.1 
 
 128-6 
 
 51.0 
 
 204.1 
 
 .65 
 
 .TO 
 
 7.8 
 
 31.3 
 
 1S.3 
 
 73.0 
 
 33.0 
 
 132.0 
 
 52.1 
 
 208.3 
 
 .TO 
 
 .75 
 
 8.2 
 
 33.0 
 
 18.9 
 
 75.6 
 
 33.9 
 
 135.5 
 
 53.1 
 
 212.6 
 
 .75 
 
 .80 
 
 8.T 
 
 34.7 
 
 19.5 
 
 78. 1 
 
 34.7 
 
 13S.9 
 
 54.2 
 
 216.9 
 
 .80 
 
 .85 
 
 i 9.1 
 
 36.5 
 
 20.2 
 
 80.8 
 
 35.6 
 
 142.4 j 
 
 55.3 
 
 221.3 
 
 .85 
 
 .90 
 
 9.6 
 
 3S.3 
 
 20.9 
 
 as.4 
 
 86.5 
 
 145.9 
 
 56.4 
 
 225.6 
 
 .90 
 
 .95 
 
 10.0 
 
 40.2 
 
 21.5 
 
 86.2 || 37.4 
 
 149.5 
 
 57.5 
 
 230.1 
 
 .95 
 
 
 5 
 
 feet. 
 
 6 
 
 feet. 
 
 7 
 
 feet. 
 
 8 
 
 feet. 
 
 
 .00 
 
 53.6 
 
 234.6 
 
 83.3 
 
 333.3 
 
 112.3 
 
 449.4 
 
 145.7 
 
 5S2.7 
 
 .00 
 
 .05 
 
 59.8 
 
 239.2 84.7 
 
 338.8 
 
 113.9 
 
 455.7 
 
 147.4 
 
 589.8 
 
 .05 
 
 .10 
 
 609 
 
 243.7 i 86.0 
 
 344.2 
 
 115.5 
 
 461.9 ji 149.3 
 
 597.0 
 
 .10 
 
 .15 
 
 62.1 
 
 248.3 i 87.4 
 
 3497 
 
 117.1 
 
 468.3 
 
 151.1 
 
 604.3 
 
 .15 
 
 .20 
 
 63.2 
 
 252.9 
 
 88.8 
 
 355.2 
 
 118.7 
 
 474.7 
 
 15-'.9 
 
 611.5 
 
 .20 
 
 .25 
 
 64.4 
 
 257.7 
 
 90.2 
 
 360.8 
 
 120.3 
 
 481.2 
 
 154.7 
 
 618.8 
 
 .25 
 
 .30 
 
 65.6 
 
 262.4 91.6 
 
 366.3 
 
 121.9 
 
 487.6 156.5 
 
 626.1 
 
 .30 
 
 .85 
 
 66.8 
 
 267.2 
 
 93.0 
 
 3*2.0 
 
 123.5 
 
 494.1 158.4 
 
 633.5 
 
 .35 
 
 .40 
 
 68.0 
 
 272.0 
 
 94.4 
 
 377.7 
 
 125.2 
 
 500 6 160.2 
 
 640.9 
 
 .40 
 
 .45 
 
 69.2 
 
 276.9 
 
 95.9 
 
 883.5 
 
 126.8 
 
 507.3 
 
 162.1 
 
 648.4 
 
 .45 
 
 .50 
 
 70.4 
 
 281.8 
 
 97.3 
 
 8S9.2 
 
 128.5 
 
 513.9 
 
 164.0 
 
 655.9 
 
 .50 
 
 .55 
 
 71.7 
 
 2S6.8 
 
 98.7 
 
 395.0 
 
 130.2 
 
 520.7 
 
 1659 
 
 663.5 
 
 .55 
 
 .60 
 
 72.9 
 
 291.8 
 
 100.2 
 
 400.9 
 
 131.8 
 
 527.4 
 
 ! 167.8 
 
 671.0 
 
 .60 
 
 .65 
 
 74.7 
 
 296.8 
 
 101.7 
 
 406.8 
 
 133.5 
 
 534.2 
 
 169.7 
 
 678.7 
 
 .65 
 
 .TO 
 
 75.5 
 
 301.9 
 
 103.2 
 
 412.7 
 
 135.2 
 
 540.9 
 
 171.6 
 
 6S6.8 
 
 .TO 
 
 .11 
 
 76.7 
 
 807.0 
 
 104.7 
 
 418.7 
 
 136.9 
 
 5478 
 
 173.5 
 
 694.1 
 
 .75 
 
 .80 
 
 78.1 
 
 312.2 
 
 106.2 
 
 424.7 
 
 138.7 
 
 554.7 
 
 175.5 
 
 701.9 
 
 .80 
 
 .85 
 
 79.3 
 
 317.5 
 
 107.7 
 
 430.8 
 
 140.4 
 
 561.7 
 
 177.4 
 
 709.7 
 
 .85 
 
 .90 
 
 80.7 
 
 322.7 
 
 109.3 
 
 437.0 
 
 142.2 
 
 568.6 
 
 179.4 
 
 717.5 
 
 .90 
 
 .95 
 
 82.0 
 
 328.0 
 
 110.8 
 
 443.2 
 
 143.9 
 
 575.7 
 
 181.3 
 
 725.4 
 
 .95 
 
 
 9 
 
 feet. 
 
 10 
 
 feet. 
 
 11 
 
 feet. 
 
 12 
 
 feet. 
 
 
 .00 
 
 183.3 
 
 733.8 
 
 225.3 
 
 901.2 
 
 271.6 
 
 1086.4 
 
 322.2 
 
 1288.9 
 
 .00 
 
 .05 
 
 185.3 
 
 741.3 
 
 227.5 
 
 910.1 
 
 274.0 
 
 1096.2 
 
 324.9 
 
 1299.5 
 
 .05 
 
 .10 
 
 I 187.3 
 
 749.4 
 
 229.7 
 
 919.0 
 
 276.5 
 
 1105.9 
 
 327.5 
 
 1310.1 
 
 .10 
 
 .15 
 
 189.4 
 
 757.5 
 
 232.0 
 
 92S.O 
 
 178.9 
 
 1115.8 
 
 330.2 
 
 1320.8 
 
 .15 
 
 .20 
 
 191.4 
 
 765.6 
 
 234.2 
 
 936.9 
 
 281.4 
 
 1125.6 
 
 332.9 
 
 1331.5 
 
 .20 
 
 .25 
 
 193.4 
 
 773.7 
 
 236.5 
 
 945.9 
 
 283.9 
 
 1135.5 
 
 335.6 
 
 1342.3 
 
 .25 
 
 .30 
 
 195.5 
 
 781.9 
 
 238.7 
 
 955.0 
 
 286.3 
 
 1145.4 
 
 338.3 
 
 1353.0 
 
 .30 
 
 .85 
 .40 
 
 197.5 
 199.6 
 
 79u2 
 
 798.4 
 
 241.0 
 243.3 
 
 964.1 
 973.2 
 
 2S9.1 
 2913 
 
 1155.4 
 1165.3 
 
 340.9 
 343.7 
 
 1363.8 
 1374.7 
 
 .85 
 .40 
 
 .45 
 
 201.7 
 
 806.8 
 
 245.6 
 
 982.5 
 
 293.8 
 
 1175.4 
 
 346.4 
 
 1385.7 
 
 .45 
 
 .50 
 
 203.8 
 
 815.1 
 
 247.9 991.7 
 
 296.4 
 
 1185.5 
 
 349.2 
 
 1396.6 
 
 .50 
 
 .55 
 
 205.9 
 
 823.6 
 
 250.2 
 
 1001.0 
 
 299.0 
 
 1195.9 
 
 351.9 
 
 1407.7 
 
 .55 
 
 .63 
 
 208.0 
 
 8320 
 
 252.6 
 
 1010.3 
 
 301.6 
 
 1206.3 
 
 354.7 
 
 1418.7 
 
 .60 
 
 .65 
 
 210.0 
 
 840.0 
 
 254.9 
 
 1019.7 
 
 304.1 
 
 1216.3 
 
 1 357.4 
 
 1429.8 
 
 .65 
 
 .TO 
 
 212.3 
 
 849.0 
 
 257.3 
 
 1029.1 
 
 306.6 
 
 1226.3 
 
 360.2 
 
 1440.9 
 
 .TO 
 
 .T5 
 
 214.4 
 
 857.7 
 
 259.6 
 
 1038.5 
 
 809.2 
 
 1236.7 I 
 
 863.0 
 
 1452.1 
 
 .75 
 
 .80 
 
 216.6 
 
 866.3 
 
 262.0 
 
 1048.0 
 
 311.8 
 
 1247.0 
 
 365.8 
 
 1463.8 
 
 .80 
 
 .85 
 
 218.7 
 
 875.0 
 
 264.4 
 
 1057.5 
 
 314.3 
 
 1257.4 
 
 368.6 
 
 1474.6 
 
 .85 
 
 .90 
 
 220.9 
 
 883.7 
 
 266.8 
 
 1067.1 
 
 317.0 
 
 1267.8 
 
 371.5 
 
 1485.9 
 
 .90 
 
 .95 
 
 223.1 
 
 892.5 
 
 269.2 
 
 1076.8 
 
 319.6 
 
 1278.8 
 
 374.3 
 
 1497.3 
 
 .95 
 
EMBANKING- LANDS FROM KIVEK-FLOODS. 
 
 159 
 
 TABLE in. (Continued.) 
 on top and 7 feet wide at base for every foot high. 
 
 Decimals of 
 
 End 
 
 4 times 
 middle 
 
 End 
 
 4 times 
 middle 
 
 End 
 
 4 times 
 middle 
 
 End 
 
 4 times 
 middle 
 
 Decimals of 
 
 a foot. 
 
 areas. 
 
 area. 
 
 areas. 
 
 area, 
 
 areas. 
 
 area. 
 
 areas. 
 
 area. 
 
 a foot. 
 
 
 13 
 
 feet. 
 
 14 
 
 feet. 
 
 15 
 
 feet. 
 
 16 
 
 feet. 
 
 
 .00 
 
 377.2 
 
 1508.6 
 
 436.4 
 
 1745.7 
 
 500.0 
 
 2000.0 
 
 568.0 
 
 2272.1 
 
 .OO 
 
 .05 
 
 8SO.O 
 
 1520.1 
 
 439.5 
 
 1758.0 
 
 503.3 
 
 2013.2 
 
 571.5 
 
 2285.9 
 
 .05 
 
 .10 
 
 3S2.9 
 
 1531.6 
 
 442.6 
 
 1770.3 
 
 506.6 
 
 2026.4 
 
 574.9 
 
 2299.7 
 
 .to 
 
 .15 
 
 3S5.8 
 
 1543.2 
 
 445.7 
 
 1782.8 
 
 509.9 
 
 2039.7 
 
 578.4 
 
 2313.8 
 
 .15 
 
 .20 
 
 388.7 
 
 1554.7 
 
 448.8 
 
 1795.2 
 
 513.2 
 
 2052.9 
 
 582.0 
 
 2328.0 
 
 .20 
 
 .25 
 
 891.6 
 
 1566.3 
 
 451.9 
 
 1807.7 
 
 516.6 
 
 2066.3 
 
 5856 
 
 2342.3 
 
 .25 
 
 .30 
 
 394.5 
 
 1577.9 
 
 455.0 
 
 1820.2 
 
 519.9 
 
 2079.7 
 
 589.2 
 
 2356.7 
 
 .30 
 
 .85 
 
 397.4 
 
 1589.7 
 
 458.2 
 
 18328 
 
 5233 
 
 2093.2 
 
 592.7 
 
 2370.9 
 
 .35 
 
 .40 
 
 400.3 
 
 1601.4 
 
 461.3 
 
 1845.3 
 
 526.6 
 
 2106.6 
 
 596.3 
 
 2385.1 
 
 .40 
 
 .45 
 
 403.3 
 
 1613.2 
 
 4645 
 
 1858.0 
 
 530.0 
 
 '2120.1 
 
 599.9 
 
 2399.5 
 
 .45 
 
 .50 
 
 406.3 
 
 1625.0 
 
 467.7 
 
 1870.7 
 
 533.4 
 
 2133.6 
 
 603.5 
 
 2418.9 
 
 .50 
 
 .55 
 
 409.2 
 
 1636.9 
 
 470.9 
 
 1883.5 
 
 5368 
 
 2147.3 
 
 607.1 
 
 2428.4 
 
 .55 
 
 .60 
 
 412.2 
 
 1648.8 
 
 474.1 
 
 1896.3 
 
 540.2 
 
 2160.9 
 
 610.7 
 
 2442.9 
 
 .60 
 
 .65 
 
 415.2 
 
 1660.8 
 
 477.3 
 
 1909.1 
 
 543.6 
 
 2174.6 
 
 614.4 
 
 2457.5 
 
 .65 
 
 .70 
 
 418.2 
 
 1672.8 
 
 480.5 
 
 1921.9 
 
 547.1 
 
 2188.3 
 
 6180 
 
 2472.0 
 
 .70 
 
 .75 
 
 421.2 
 
 1684.8 
 
 433.7 
 
 1934.8 
 
 550.5 
 
 2202.1 
 
 621.7 
 
 2486.7 
 
 .75 
 
 .SO 
 
 424.2 
 
 1696.9 1 
 
 486.9 
 
 1947.8 
 
 554.0 
 
 22159 
 
 625.3 
 
 2501.3 
 
 .80 
 
 .85 
 
 427.2 
 
 1709.0 
 
 490.2 
 
 1960.8 
 
 557.4 
 
 2229.8 
 
 629.0 
 
 2516.1 
 
 .85 
 
 .90 
 
 430.3 
 
 1721.2 
 
 493.4 
 
 1973.8 
 
 560.9 
 
 2243.7 
 
 632.7 
 
 2530.8 
 
 .90 
 
 .95 
 
 433.4 
 
 1733.5 
 
 496.7 
 
 1986.9 
 
 564.5 
 
 22579 
 
 636.4 
 
 2545.7 
 
 .95 
 
 
 17 
 
 feet. 
 
 18 
 
 feet. 
 
 19 
 
 feet. 
 
 
 
 feet. 
 
 
 .00 
 
 640.1 
 
 2560.5 
 
 716.7 
 
 2866.7 
 
 797.5 
 
 3190.1 
 
 882.7 
 
 3530.9 
 
 .00 
 
 .05 
 
 643.8 
 
 2575.4 
 
 720.6 
 
 2882.5 
 
 801.7 
 
 3206.8 
 
 887.1 
 
 35484 
 
 .05 
 
 .10 
 
 647.6 
 
 2590.3 
 
 724.6 
 
 2898.2 
 
 805.9 
 
 3223.4 
 
 891.5 
 
 35659 
 
 .10 
 
 .15 
 
 651.3 
 
 2605.3 
 
 728.5 
 
 2914.1 
 
 810.0 
 
 8240.2 
 
 895.9 
 
 3583.5 
 
 .15 
 
 .20 
 
 655.1 
 
 2620.3 
 
 732.5 
 
 2930.0 
 
 814.2 
 
 3256.9 
 
 900.3 
 
 3601.1 
 
 .20 
 
 .25 
 
 658.8 
 
 2635.4 
 
 736.5 
 
 2946.0 
 
 818.4 
 
 8273.fi 
 
 904.7 
 
 3618.8 
 
 .25 
 
 .30 
 
 662.6 
 
 2650.5 
 
 740.5 
 
 2961.9 
 
 822.6 
 
 3290.4 
 
 909.1 
 
 3636.5 
 
 .30 
 
 .35 
 
 6fi6.4 
 
 2665.7 
 
 744.5 
 
 2978.0 
 
 826.9 
 
 3307.8 
 
 913.6 
 
 3654.8 
 
 .85 
 
 .40 
 
 670.2 
 
 2680.9 
 
 748.5 
 
 2994.0 
 
 831.1 
 
 3324.4 
 
 918.0 
 
 3672.0 
 
 .40 
 
 .45 
 
 674.0 
 
 2696.2 
 
 752.5 
 
 3010.1 
 
 835.3 
 
 3341.3 
 
 922.4 
 
 8689.8 
 
 .45 
 
 .50 
 
 677.9 
 
 2711.4 
 
 756.6 
 
 8026.2 
 
 839.6 
 
 8358.3 
 
 926.9 
 
 3707.7 
 
 .50 
 
 .55 
 
 681.7 
 
 2726.8 
 
 760.6 
 
 3042.5 
 
 843.8 
 
 3375.4 
 
 931.4 
 
 3725.7 
 
 .55 
 
 .60 
 
 685.5 
 
 2742.1 
 
 764.7 
 
 3058.7 
 
 8481 
 
 8392.5 
 
 935.9 
 
 3743.6 
 
 .60 
 
 .65 
 
 689.4 
 
 2757.6 
 
 763.7 
 
 3075.0 
 
 852.4 
 
 3409.7 
 
 940.4 
 
 3761.7 
 
 .65 
 
 .70 
 
 693.3 
 
 2773.0 
 
 772.8 
 
 8091.3 
 
 856.7 
 
 8426.8 
 
 9449 
 
 37797 
 
 .70 
 
 .75 
 
 697.1 
 
 2788.6 
 
 776.9 
 
 3107.7 
 
 861.0 
 
 3444.0 1 
 
 949.4 
 
 3797.8 
 
 .75 
 
 .80 
 
 701.0 
 
 2804.1 
 
 781.0 
 
 8124.1 
 
 865-8 
 
 3461.3 
 
 954.0 
 
 3815.9 
 
 .80 
 
 .85 
 
 704.9 
 
 2819.7 
 
 7851 
 
 3140.6 
 
 869.7 
 
 3478.7 
 
 958.5 
 
 8834.1 
 
 .85 
 
 .90 
 
 708.8 
 
 2835.3 
 
 789.0 
 
 3157.0 
 
 874.0 
 
 3496.1 
 
 963.1 
 
 8852.3 
 
 .SO 
 
 .95 
 
 712.7 
 
 2851.0 
 
 793.4 
 
 3178.6 
 
 878.4 
 
 3513.5 
 
 967.6 
 
 8870.6 
 
 .95 
 
 
 21 
 
 feet. 
 
 22 
 
 feet. 
 
 23 
 
 feet. 
 
 24 
 
 feet. 
 
 
 .OO 
 
 972.2 
 
 3888.9 
 
 1066.1 
 
 4264.2 
 
 1164.2 
 
 4656.8 
 
 1266.7 
 
 5066.7 
 
 .QO 
 
 .05 
 
 976.9 
 
 3907.7 
 
 1070.9 
 
 4283.5 
 
 1169.2 
 
 4676.9 
 
 1271.9 
 
 5087.6 
 
 .05 
 
 .10 
 
 981.4 
 
 3925.6 
 
 1075.7 
 
 4302.7 
 
 1174.3 
 
 4697.0 
 
 1277.2 
 
 5108.6 
 
 .10 
 
 .15 
 
 986.0 
 
 8944.1 
 
 1080.5 
 
 4322.0 
 
 1179.3 
 
 4717.1 
 
 1282.4 
 
 5129.7 
 
 .15 
 
 .20 
 
 990.6 
 
 3962.6 
 
 1085.3 
 
 4341.3 
 
 1184.3 
 
 4737.4 
 
 1287.7 
 
 5150.7 
 
 .20 
 
 .25 
 
 994.8 
 
 3981.2 
 
 1090.2 
 
 4360.8 
 
 1189.4 
 
 4757.6 
 
 1292.9 
 
 5171.8 
 
 .25 
 
 .30 
 
 999.9 1 3999.7 
 
 1095.0 
 
 4380.2 
 
 1194.5 
 
 4777.9 
 
 1298.3 
 
 5193.0 
 
 .33 
 
 .35 
 
 1004.6 
 
 4018.3 
 
 1099.9 
 
 4399.7 
 
 1199.6 
 
 4798.3 
 
 1303.6 
 
 5214.3 
 
 .85 
 
 .40 
 
 1009.2 
 
 4036.9 
 
 11048 
 
 4419.2 
 
 1204.7 
 
 4818.7 
 
 1308.9 
 
 5235.5 
 
 .40 
 
 .45 
 
 1013.9 
 
 4055.7 
 
 1109.7 
 
 4438.8 
 
 12098 
 
 4839.2 
 
 1314.2 
 
 5256.8 
 
 .45 
 
 .50 
 
 1018.6 
 
 4074.4 
 
 1114.6 
 
 4458.3 
 
 1214.9 
 
 4859.6 
 
 1319.5 
 
 5278.1 
 
 .50 
 
 .55 
 
 1023.3 
 
 4093.2 
 
 1119.5 
 
 4478.0 
 
 1220-0 
 
 48801 
 
 1824.9 
 
 5299.5 
 
 .55 
 
 .60 
 
 1028.0 
 
 4112.0 
 
 1124.4 
 
 4497.7 
 
 1225.2 
 
 4900.6 
 
 1330.2 
 
 5320.9 
 
 .60 
 
 .65 
 
 1032.7 
 
 4130.9 
 
 1129.4 
 
 4517.5 
 
 1230.3 
 
 4921.3 
 
 1335.6 
 
 5342.4 
 
 .65 
 
 .70 
 
 1037.4 
 
 4149.8 
 
 1134.3 
 
 4537.2 
 
 1235.5 
 
 4941.9 
 
 1341.0 
 
 5363.9 
 
 .70 
 
 .75 
 
 1042.2 
 
 4168.8 II 1139.2 
 
 4557.0 
 
 1240.6 
 
 4962.6 
 
 1346.4 
 
 5385.5 
 
 .75 
 
 .80 
 
 1046.9 
 
 4187.8 
 
 1144.2 
 
 4576.9 
 
 1245.8 
 
 4983.3 
 
 1351.8 
 
 5407.0 
 
 .80 
 
 .85 
 
 1051.7 
 
 4206.8 
 
 11492 
 
 4596.8 
 
 1251.0 
 
 5004.1 
 
 1357.1 
 
 5428.6 
 
 .85 
 
 .90 
 
 1056.5 
 
 4225.9 
 
 1154.2 
 
 4616.8 
 
 1256.2 
 
 5024.0 
 
 1362.6 
 
 5450.2 
 
 .90 
 
 .95 
 
 1061.2 
 
 4245.0 
 
 1159.2 
 
 4636.8 
 
 1261.4 
 
 5045.8 
 
 1368.0 
 
 5472.0 
 
 .95 
 
 i 
 
 
 
 
 
 
 
 
 
 
160 
 
 PRINCIPLES AND PRACTICE OF 
 
 AUXILIARY TO TABLE IV. 
 
 WHEN THE AREAS CONTAIN DECIMAL PARTS. 
 
 Decimal of Areas. 
 
 Decimal 
 Cubic Yards 
 Corresponding. 
 
 .00 
 
 .0 
 
 .17 
 
 .1 
 
 .33 
 
 .2 
 
 .50 
 
 .3 
 
 .66 
 
 .4 ' 
 
 .83 
 
 .5 
 
 1.00 
 
 .6 
 
 N.B. When the square area consists of a whole number and of 
 decimal parts of a whole number, the cubic yards corresponding to those 
 decimal parts, as given in the subjoined Auxiliary Table, are to be added 
 to the cubic yards corresponding to the whole number as set forth in 
 Table IV. 
 
EMBANKING LANDS FROM lilYER-FLOODS. 
 
 161 
 
 TABLE IV. 
 
 Table of Cubic Yards corresponding to areas in square feet. 
 
 Areas 
 in square feet. 
 
 Cubic yards 
 corresponding. 
 
 Areas 
 [ in Equate feet. 
 
 Cubic yard', 
 corresponding. 
 
 * 
 
 Cubic yards 
 corresponding. 
 
 A reas 
 in square feet. 
 
 fcb 
 
 11 
 
 li 
 
 Areas 
 in square feet. 
 
 Cubic yards 
 corresponding. 
 
 <l 
 
 Cubic yards 
 corresponding. 
 
 1 
 
 0.6 
 
 5 
 
 40.1 
 
 9 
 
 79.6 
 
 3 
 
 119.1 
 
 7 
 
 15S.6 
 
 1 
 
 198.1 
 
 2 
 
 1.2 
 
 6 
 
 40.7 
 
 130 
 
 80.2 
 
 4 
 
 119.7 
 
 8 
 
 159.2 
 
 2 
 
 198.8 
 
 3 
 
 1.9 
 
 7 
 
 41.4 
 
 1 
 
 80.9 
 
 5 
 
 120.4 
 
 9 
 
 159.9 
 
 3 
 
 199.4 
 
 4 
 
 2.5 
 
 8 
 
 42.0 
 
 2 
 
 81.5 
 
 6 
 
 121.0 
 
 260 
 
 160.5 
 
 4 
 
 200.1 
 
 5 
 
 3.1 
 
 9 
 
 42.6 
 
 8 
 
 82.1 
 
 7 
 
 121.6 
 
 1 
 
 161.1 
 
 5 
 
 2006 
 
 6 
 
 3.7 
 
 70 
 
 43.2 
 
 4 
 
 82.7 
 
 8 
 
 122.2 
 
 2 
 
 161.7 
 
 6 
 
 201.2 
 
 7 
 
 4.3 
 
 1 
 
 43.8 
 
 5 
 
 83.3 
 
 9 
 
 122.8 
 
 3 
 
 162.3 
 
 7 
 
 201.8 
 
 8 
 
 4.9 
 
 2 
 
 444 
 
 6 
 
 83.9 
 
 200 
 
 123.4 
 
 4 
 
 162.9 
 
 8 
 
 202.4 
 
 9 
 
 5.5 
 
 8 
 
 45.1 
 
 7 
 
 84.6 
 
 1 
 
 124.1 
 
 5 
 
 163.6 
 
 9 
 
 203.1 
 
 10 
 
 6.2 
 
 4 
 
 45.7 
 
 8 
 
 85.2 
 
 2 
 
 124.7 
 
 6 
 
 164.2 
 
 330 
 
 203.7 
 
 1 
 
 6.8 
 
 5 
 
 46.3 
 
 9 
 
 85.8 
 
 3 
 
 125.3 
 
 7 
 
 164.8 
 
 1 
 
 204.3 
 
 2 
 
 7.4 
 
 6 
 
 46.9 
 
 140 
 
 86.4 
 
 4 
 
 125.9 
 
 s 
 
 165.4 
 
 2 
 
 204.9 
 
 3 
 
 8.0 
 
 7 
 
 47.5 
 
 1 
 
 87.0 
 
 5 
 
 126.5 
 
 9 
 
 166.0 
 
 3 
 
 205.5 
 
 4 
 
 8.6 
 
 8 
 
 48.1 
 
 2 
 
 87.6 
 
 6 
 
 127.1 
 
 270 
 
 166.7 
 
 4 
 
 206.2 
 
 5 
 
 9.3 
 
 9 
 
 48.8 
 
 S 
 
 88.3 
 
 7 
 
 127.8 
 
 1 
 
 167.3 
 
 5 
 
 206.8 
 
 6 
 
 9.9 
 
 80 
 
 49.4 
 
 4 
 
 88.9 
 
 8 
 
 128.4 
 
 2 
 
 167.9 
 
 6 
 
 207.4 
 
 7 
 
 10.5 
 
 1 
 
 50.0 
 
 5 
 
 89.5 
 
 9 
 
 129.0 
 
 8 
 
 168.5 
 
 7 
 
 208.0 
 
 8 
 
 11.1 
 
 2 
 
 50.6 
 
 6 
 
 90.1 
 
 21O 
 
 129.6 
 
 4 
 
 169.1 
 
 8 
 
 208.6 
 
 9 
 
 11.7 
 
 3 
 
 51.2 
 
 7 
 
 90.7 
 
 1 
 
 130.2 
 
 5 
 
 169.7 
 
 9 
 
 2092 
 
 20 
 
 12.3 
 
 4 
 
 51.8 
 
 8 
 
 91.4 
 
 2 
 
 130.9 
 
 6 
 
 170.4 
 
 340 
 
 209.9 
 
 1 
 
 13.0 
 
 5 
 
 52.5 
 
 9 
 
 92.0 
 
 3 
 
 131.5 
 
 7 
 
 171.0 
 
 1 
 
 210.5 
 
 2 
 
 13.6 
 
 6 
 
 53.1 
 
 ISO 
 
 92.6 
 
 4 
 
 132.1 
 
 8 
 
 171.6 
 
 2 
 
 211.1 
 
 3 
 
 14.2 
 
 7 
 
 53.7 
 
 1 
 
 93.2 
 
 5 
 
 132.7 
 
 9 
 
 172.2 
 
 3 
 
 211.7 
 
 4 
 
 14.8 
 
 8 
 
 54.3 
 
 2 
 
 93.8 
 
 6 
 
 133.8 
 
 280 
 
 172.8 
 
 4 
 
 212.3 
 
 5 
 
 15.4 
 
 9 
 
 54.9 
 
 3 
 
 94.4 
 
 7 
 
 133.9 
 
 1 
 
 173.4 
 
 5 
 
 212.9 
 
 6 
 
 16.0 
 
 90 
 
 55.5 
 
 4 
 
 95.1 
 
 8 
 
 134.6 
 
 2 
 
 174.1 
 
 6 
 
 213.6 
 
 7 
 
 16.7 
 
 1 
 
 56.2 
 
 5 
 
 95.7 
 
 9 
 
 135.2 
 
 3 
 
 174.7 
 
 7 
 
 214.2 
 
 8 
 
 17.3 
 
 2 
 
 56.8 
 
 6 
 
 96.3 
 
 220 
 
 135.8 
 
 4 
 
 175.3 
 
 8 
 
 214.8 
 
 9 
 
 17.9 
 
 8 
 
 57.4 
 
 7 
 
 96.9 
 
 1 
 
 136.4 
 
 5 
 
 175.9 
 
 9 
 
 215.4 
 
 30 
 
 18.5 
 
 4 
 
 58.0 
 
 8 
 
 97.5 
 
 2 
 
 137.0 
 
 6 
 
 176.5 
 
 350 
 
 216.0 
 
 1 
 
 19.1 
 
 5 
 
 58.6 
 
 9 
 
 98.1 
 
 3 
 
 137.6 
 
 7 
 
 177.1 
 
 1 
 
 216.7 
 
 2 
 
 19.8 
 
 6 
 
 59.3 
 
 160 
 
 98.8 
 
 4 
 
 138.3 
 
 8 
 
 177.8 
 
 2 
 
 217.3 
 
 3 
 
 20.4 
 
 7 
 
 59.9 
 
 1 
 
 99.4 
 
 5 
 
 138.9 
 
 9 
 
 178.4 
 
 3 
 
 217.9 
 
 4 
 
 21.0 
 
 S 
 
 60.5 
 
 2 
 
 100.0 
 
 6 
 
 139.5 
 
 290 
 
 179.0 i 
 
 4 
 
 218.5 
 
 5 
 
 21.6 
 
 9 
 
 61.1 
 
 8 
 
 100.6 
 
 7 
 
 140.1 
 
 l 
 
 179.6 
 
 5 
 
 219.1 
 
 6 
 
 22.2 
 
 1OO 
 
 61.7 
 
 4 
 
 101.2 
 
 8 
 
 140.7 
 
 2 
 
 180.2 
 
 6 
 
 219.7 
 
 7 
 
 22.8 
 
 1 
 
 62.8 
 
 5 
 
 101.8 
 
 9 
 
 141.4 
 
 3 
 
 180.9 
 
 7 
 
 220.4 
 
 8 
 
 23.5 
 
 2 
 
 63.0 
 
 6 
 
 102.5 
 
 230 
 
 142.0 
 
 4 
 
 181.5 
 
 S 
 
 221.0 
 
 9 
 
 24.1 
 
 8 
 
 63.6 
 
 7 
 
 103.1 
 
 1 
 
 142.6 
 
 5 
 
 182.1 
 
 9 
 
 221.6 
 
 40 
 
 24.7 
 
 4 
 
 64.2 
 
 8 
 
 103.7 
 
 2 
 
 143.2 
 
 6 
 
 182. 7 
 
 360 
 
 222.2 
 
 1 
 
 25.8 
 
 5 
 
 64.8 
 
 9 
 
 104.3 
 
 8 
 
 143.8 
 
 7 
 
 183.3 
 
 1 
 
 222.8 
 
 2 
 
 25.9 
 
 6 
 
 65.4 
 
 170 
 
 104.9 
 
 4 
 
 144.4 
 
 8 
 
 183.9 
 
 2 
 
 223.4 
 
 8 
 
 26.5 
 
 7 
 
 66.0 
 
 1 
 
 105.5 
 
 5 
 
 145.1 
 
 9 
 
 184.6 
 
 3 
 
 224.1 
 
 4 
 
 27.1 
 
 8 
 
 667 
 
 2 
 
 106.2 
 
 6 
 
 145.7 
 
 300 
 
 185.2 
 
 4 
 
 224.7 
 
 5 
 
 27.8 
 
 9 
 
 67.3 
 
 3 
 
 106.8 
 
 7 
 
 146.3 
 
 1 
 
 185.8 
 
 5 
 
 225.8 
 
 6 
 
 28.4 
 
 110 
 
 67.9 
 
 4 
 
 107.4 
 
 8 
 
 146.9 
 
 2 
 
 1S6.4 
 
 (j 
 
 225.9 
 
 7 
 
 29.0 
 
 1 
 
 68.5 
 
 5 
 
 10S.O 
 
 9 
 
 147.5 
 
 3 
 
 187.0 
 
 7 
 
 226.5 
 
 8 
 
 29.6 
 
 2 
 
 69.1 
 
 6 
 
 108.6 
 
 240 
 
 148.1 
 
 4 
 
 187.6 
 
 8 
 
 227.1 
 
 9 
 
 30.2 
 
 8 
 
 69.7 
 
 7 
 
 109.3 
 
 1 
 
 148. 8 
 
 5 
 
 188.3 
 
 9 
 
 227.8 
 
 50 
 
 30.9 
 
 4 
 
 70.4 
 
 8 
 
 109.9 
 
 2 
 
 149.4 
 
 6 
 
 1S8.9 
 
 C7O 
 
 228.4 
 
 1 
 
 31.5 
 
 5 
 
 71.0 
 
 9 
 
 110.5 
 
 8 
 
 150.0 
 
 7 
 
 1S9.5 
 
 1 
 
 229.0 
 
 2 
 
 82.1 
 
 6 
 
 71.6 
 
 180 
 
 111.1 
 
 4 
 
 150.6 
 
 8 
 
 190.1 
 
 2 
 
 229.6 
 
 8 
 
 32.7 
 
 7 
 
 72.2 
 
 1 
 
 111.7 
 
 5 
 
 151.2 
 
 9 
 
 190.7 
 
 8 
 
 230.2 
 
 4 
 
 83.3 
 
 8 
 
 72.8 
 
 2 
 
 112.3 
 
 6 
 
 151.8 
 
 31O 
 
 191.3 
 
 4 
 
 230.8 
 
 5 
 
 33.9 
 
 9 
 
 73.4 
 
 3 
 
 112.9 
 
 7 
 
 152.4 
 
 1 
 
 192.0 
 
 5 
 
 281.5 
 
 6 
 
 84.6 
 
 120 
 
 74.1 
 
 4 
 
 113.6 
 
 8 
 
 153.1 
 
 2 
 
 192.6 
 
 6 
 
 232.1 
 
 7 
 
 35.2 
 
 1 
 
 74.7 
 
 5 
 
 114.2 
 
 9 
 
 153.7 
 
 8 
 
 193.2 
 
 7 
 
 232.7 
 
 8 
 
 35.8 
 
 2 
 
 753 
 
 6 
 
 114.8 
 
 250 
 
 154.3 
 
 4 
 
 193.8 
 
 8 
 
 233.8 
 
 9 
 
 36.4 
 
 3 
 
 75.9 
 
 7 
 
 115.4 
 
 1 
 
 154.9 
 
 5 
 
 194.4 
 
 9 
 
 233.9 
 
 6O 
 
 87.0 
 
 4 
 
 76.5 
 
 8 
 
 116.0 
 
 2 
 
 155.5 
 
 6 
 
 195.1 
 
 380 
 
 
 1 
 
 37.6 
 
 5 
 
 77.2 
 
 9 
 
 116.7 
 
 3 
 
 156.2 
 
 7 
 
 195.7 
 
 1 
 
 235/2 
 
 2 
 
 38.3 
 
 6 
 
 77.8 
 
 190 
 
 117.3 
 
 4 
 
 156.8 
 
 8 
 
 196.3 
 
 2 
 
 235.8 
 
 3 
 
 38.9 
 
 7 
 
 78.4 
 
 1 
 
 117.9 
 
 5 
 
 157.4 
 
 9 
 
 196.9 
 
 3 
 
 236.4 
 
 4 
 
 39.5 
 
 8 
 
 79.0 
 
 2 
 
 118.5 
 
 6 
 
 158.0 
 
 320 
 
 197.5 
 
 4 
 
 237.0 
 
162 
 
 PEINCIPLES AND PKACTICE OF 
 
 AUXILIARY TO TABLE IV. 
 
 WHEN THE AREAS CONTAIN DECIMAL PARTS. 
 
 Decimal of Areas. 
 
 Decimal 
 Cubic Yards 
 Corresponding. 
 
 .00 
 
 .0 
 
 .17 
 
 .1 
 
 .33 
 
 .2 
 
 .50 
 
 .3 
 
 .66 
 
 .4 
 
 .83 
 
 .5 
 
 1.00 
 
 .6 
 
 N.B. When the square area consists of a whole number and of 
 decimal parts of a whole number, the cubic yards corresponding to those 
 decimal parts, as given in the subjoined Auxiliary Table, are to be added 
 to the cubic yards corresponding to the whole number as set forth in 
 Table IV. 
 
PKINCIPLES AND PEACTICE OF 
 
 163 
 
 TABLE IV. ( Continued. ) 
 Table of Cubic Yards corresponding to Areas in square feet. 
 
 ^.reaS 
 uare feet. 
 
 ic yards 
 
 spending. 
 
 1 2 
 
 if 
 
 ! 
 
 
 
 is 
 
 S. cS 
 
 || 
 || 
 
 1 
 || 
 
 || 
 g| 
 
 ll 
 
 cr ^ 
 
 *p.9 
 o ft 
 
 2 
 is 
 
 n'c yards 
 spending. 
 
 "5T 
 
 6 S 
 
 ~ 
 
 2 S 
 ^8 
 
 *s 
 
 a. 
 
 *! 
 
 .2" 
 
 if 
 
 .5 
 
 ^8 
 
 ""sr 
 
 a 
 
 og 
 
 5 
 
 237.6 
 
 9 
 
 2TT.2 
 
 8 
 
 316.6 
 
 7 
 
 356.1 
 
 1 
 
 395.7 
 
 5 
 
 435.2 
 
 6 
 
 288. 2 
 
 450 
 
 27T.8 
 
 4 
 
 817.3 
 
 8 
 
 356.7 
 
 2 
 
 396.3 
 
 6 
 
 435.8 
 
 7 
 
 238.9 
 
 1 
 
 278.4 
 
 5 
 
 817.9 
 
 9 
 
 357.3 
 
 3 
 
 3969 
 
 7 
 
 436.4 
 
 8 
 
 239.5 
 
 2 
 
 279.0 
 
 6 
 
 318.5 
 
 58O 
 
 358.0 
 
 4 
 
 3975 
 
 8 
 
 437.0 
 
 9 
 
 240.1 
 
 3 
 
 279.6 
 
 7 
 
 319.1 
 
 1 
 
 358.6 
 
 5 
 
 398.1 
 
 9 
 
 437.6 
 
 390 
 
 240.7 
 
 4 
 
 280.2 
 
 8 
 
 319.7 
 
 2 
 
 359.2 
 
 6 
 
 398.7 
 
 710 
 
 438.3 
 
 1 
 
 241.3 
 
 5 
 
 280.9 
 
 9 
 
 320.3 
 
 3 
 
 359.8 
 
 7 
 
 399.4 
 
 1 
 
 438.9 
 
 2 
 
 241.9 
 
 6 
 
 281.5 
 
 520 
 
 321.0 
 
 4 
 
 360.4 
 
 8 
 
 400.0 
 
 2 
 
 439.5 
 
 3 
 
 242.6 
 
 7 
 
 282.1 
 
 1 
 
 321.6 
 
 5 
 
 361.0 
 
 9 
 
 400.6 
 
 8 
 
 440.1 
 
 4 
 
 2432 
 
 8 
 
 282.7 
 
 2 
 
 322.2 
 
 6 
 
 861.7 
 
 650 
 
 401.2 
 
 4 
 
 440.7 
 
 5 
 
 243.8 
 
 9 
 
 283.3 
 
 ft 
 
 322.8 
 
 7 
 
 362.3 
 
 1 
 
 401.8 
 
 5 
 
 441.3 
 
 6 
 
 244.4 
 
 460 
 
 283.9 
 
 4 
 
 323.4 
 
 8 
 
 362.9 
 
 2 
 
 402.4 
 
 6 
 
 442.0 
 
 7 
 
 245.0 
 
 1 
 
 284.6 
 
 5 
 
 324.0 
 
 9 
 
 863.5 
 
 3 
 
 403.1 
 
 7 
 
 442.6 
 
 8 
 
 245.7 
 
 2 
 
 285.2 
 
 6 
 
 824.7 
 
 590 
 
 364.1 
 
 4 
 
 403.7 
 
 8 
 
 443.2 
 
 9 
 
 246.8 
 
 3 
 
 285.8 
 
 7 
 
 325.3 
 
 1 
 
 364.7 
 
 5 
 
 404.3 
 
 9 
 
 443.8 
 
 400 
 
 246.9 
 
 4 
 
 28(5.4 
 
 8 
 
 825.9 
 
 2 
 
 865.4 
 
 6 
 
 4049 
 
 720 
 
 444.4 
 
 1 
 
 247.5 
 
 5 
 
 287.0 
 
 9 
 
 326.5 
 
 3 
 
 866.0 
 
 7 
 
 405.5 
 
 1 
 
 445.0 
 
 2 
 
 248.1 
 
 6 
 
 287.6 
 
 530 
 
 327.1 
 
 4 
 
 366.6 
 
 8 
 
 406.1 
 
 2 
 
 445.7 
 
 8 
 
 248.7 
 
 7 
 
 2S8.8 
 
 1 
 
 &27.7 
 
 5 
 
 867-3 
 
 9 
 
 406.8 
 
 3 
 
 446.8 
 
 4 
 
 249.4 
 
 8 
 
 288.9 
 
 2 
 
 328.4 
 
 6 
 
 367.9 
 
 66O 
 
 407.4 
 
 4 
 
 446.9 
 
 5 
 
 250.0 
 
 9 
 
 289.5 
 
 8 
 
 329.0 
 
 7 
 
 368.5 
 
 1 
 
 408.0 
 
 5 
 
 447.5 
 
 6 
 
 250.6 
 
 470 
 
 290.1 
 
 4 
 
 329.6 
 
 8 
 
 369.1 
 
 2 
 
 408.6 
 
 6 
 
 448.1 
 
 7 
 
 251.2 
 
 1 
 
 290.7 
 
 5 
 
 330.2 
 
 9 
 
 369.T 
 
 3 
 
 409.2 
 
 7 
 
 448.7 
 
 8 
 
 251.8 
 
 2 
 
 291.3 
 
 6 
 
 830.8 
 
 600 
 
 370.4 
 
 4 
 
 4C9.8 
 
 8 
 
 449.4 
 
 9 
 
 252.4 
 
 3 
 
 292.0 
 
 7 
 
 831.4 
 
 1 
 
 871-0 
 
 5 
 
 410.5 
 
 9 
 
 450.0 
 
 410 
 
 253.1 
 
 4 
 
 292.6 
 
 8 
 
 332.1 
 
 2 
 
 371.6 
 
 6 
 
 411.1 
 
 730 
 
 450.6 
 
 1 
 
 253.7 
 
 5 
 
 292.2 
 
 9 
 
 832.7 
 
 3 
 
 372.2 
 
 7 
 
 4117 
 
 1 
 
 451.2 
 
 2 
 
 254.3 
 
 6 
 
 293.8 
 
 540 
 
 333.3 
 
 4 
 
 372.8 
 
 8 
 
 4123 
 
 2 
 
 451.8 
 
 3 
 
 254.9 
 
 7 
 
 294.4 
 
 1 
 
 333.9 
 
 5 
 
 373.4 
 
 9 
 
 413.0 
 
 3 
 
 452.4 
 
 4 
 
 255.5 
 
 8 
 
 295.0 
 
 2 
 
 334.5 
 
 6 
 
 374.1 
 
 67O 
 
 413.6 
 
 4 
 
 458.1 
 
 5 
 
 256.2 
 
 9 
 
 295.T 
 
 3 
 
 335.1 
 
 7 
 
 874.7 
 
 1 
 
 414.3 
 
 5 
 
 453.7 
 
 6 
 
 256.8 
 
 480 
 
 29G.3 
 
 4 
 
 335.8 
 
 8 
 
 875.3 
 
 2 
 
 414.9 
 
 6 
 
 454.3 
 
 7 
 
 257.4 
 
 1 
 
 296.9 
 
 5 
 
 336.4 
 
 9 
 
 375.9 
 
 3 
 
 415.5 
 
 7 
 
 454.9 
 
 8 
 
 258.0 
 
 2 
 
 297.5 
 
 6 
 
 337.0 
 
 610 
 
 376.5 
 
 4 
 
 416.1 
 
 8 
 
 455.5 
 
 9 
 
 258.6 
 
 3 
 
 298.1 
 
 7 
 
 337.6 
 
 1 
 
 377.2 
 
 5 
 
 416.7 
 
 9 
 
 456.1 
 
 42O 
 
 259.2 
 
 4 
 
 298.8 
 
 8 
 
 338.2 
 
 2 
 
 377.8 
 
 6 
 
 417.3 
 
 740 
 
 456.8 
 
 1 
 
 259.9 
 
 5 
 
 2994 
 
 9 
 
 338.8 
 
 8 
 
 378.4 
 
 7 
 
 417.9 
 
 1 
 
 457.4 
 
 2 
 
 260.5 
 
 6 
 
 300.0 
 
 550 
 
 339.5 
 
 4 
 
 879.0 
 
 8 
 
 418.5 
 
 2 
 
 458.0 
 
 3 
 
 261.1 
 
 7 
 
 300.0 
 
 1 
 
 840.1 
 
 5 
 
 379.6 
 
 9 
 
 419.1 
 
 3 
 
 458.6 
 
 4 
 
 261.7 
 
 8 
 
 801.2 
 
 2 
 
 340.7 
 
 6 
 
 8802 
 
 680 
 
 419.7 
 
 4 
 
 459.2 
 
 5 
 
 262.3 
 
 9 
 
 301.8 
 
 3 
 
 341.3 
 
 7 
 
 880. 9 
 
 1 
 
 420.4 
 
 5 
 
 459.8 
 
 6 
 
 202.9 
 
 490 
 
 302.5 
 
 4 
 
 341.9 
 
 8 
 
 381.5 
 
 2 
 
 421-0 
 
 6 
 
 460.5 
 
 7 
 
 263.6 
 
 1 
 
 303.1 
 
 5 
 
 342.5 
 
 9 
 
 382. 1 
 
 3 
 
 421.6 
 
 7 
 
 461.1 
 
 8 
 
 264.2 
 
 2 
 
 303.7 
 
 6 
 
 843.2 
 
 620 
 
 382.7 
 
 4 
 
 422.2 
 
 8 
 
 461.7 
 
 9 
 
 264.8 
 
 3 
 
 304.3 
 
 7 
 
 343.8 
 
 1 
 
 383.3 
 
 5 
 
 422.8 
 
 9 
 
 462.3 
 
 43O 
 
 265.4 
 
 4 
 
 304.9 
 
 8 
 
 8444 
 
 2 
 
 883.9 
 
 6 
 
 423.4 
 
 750 
 
 463.0 
 
 1 
 
 266.0 
 
 5 
 
 305.5 
 
 9 
 
 345.0 
 
 3 
 
 384.6 
 
 7 
 
 424.1 
 
 1 
 
 463.6 
 
 2 
 
 266.7 
 
 6 
 
 806.2 
 
 560 
 
 345.6 
 
 4 
 
 885.2 
 
 S 
 
 424.7 
 
 2 
 
 464.2 
 
 8 
 
 267.3 
 
 7 
 
 306.8 
 
 1 
 
 346.2 
 
 5 
 
 385.8 
 
 9 
 
 425.3 
 
 3 
 
 464.8 
 
 4 
 
 267.9 
 
 8 
 
 807.4 
 
 2 
 
 346.9 
 
 6 
 
 386.4 
 
 690 
 
 425.9 
 
 4 
 
 465.4 
 
 5 
 
 268.5 
 
 9 
 
 308.0 
 
 3 
 
 847.5 
 
 7 
 
 387.0 
 
 1 
 
 426.5 
 
 5 
 
 466.0 
 
 6 
 
 269.1 
 
 500 
 
 308.6 
 
 4 
 
 348.1 
 
 8 
 
 387.6 
 
 2 
 
 427.2 
 
 6 
 
 466.7 
 
 7 
 
 269.7 
 
 1 
 
 309.2 
 
 5 
 
 348.7 
 
 9 
 
 388.3 
 
 8 
 
 4278 
 
 7 
 
 467.3 
 
 8 
 
 270.4 
 
 2 
 
 809.9 
 
 6 
 
 349.3 
 
 630 
 
 888.9 
 
 4 
 
 428.4 
 
 8 
 
 467.9 
 
 9 
 
 271.0 
 
 8 
 
 310.5 
 
 7 
 
 349.9 
 
 1 
 
 389.5 
 
 5 
 
 429.0 
 
 9 
 
 468.5 
 
 44O 
 
 271.6 
 
 4 
 
 311.1 
 
 8 
 
 350.6 
 
 2 
 
 390.1 
 
 6 
 
 429.6 
 
 760 
 
 469.1 
 
 1 
 
 272.2 
 
 5 
 
 311.7 
 
 9 
 
 351.2 
 
 3 
 
 390.7 
 
 7 
 
 430.2 
 
 1 
 
 469.7 
 
 2 
 
 272.8 
 
 6 
 
 312.3 
 
 570 
 
 351.8 
 
 4 
 
 391.3 
 
 8 
 
 430.9 
 
 2 
 
 470.4 
 
 3 
 
 273.4 
 
 7 
 
 312.9 
 
 1 
 
 352.4 
 
 5 
 
 892.0 
 
 9 
 
 431.5 
 
 8 
 
 471.0 
 
 4 
 
 274.1 
 
 8 
 
 313.6 
 
 2 
 
 353.0 
 
 6 
 
 392.6 
 
 700 
 
 432.1 
 
 4 
 
 471.6 
 
 5 
 
 274.7 
 
 9 
 
 314.2 
 
 8 
 
 853.6 
 
 7 
 
 893.2 
 
 1 
 
 4327 
 
 5 
 
 472.2 
 
 6 
 
 275.3 
 
 51O 
 
 814.8 
 
 4 
 
 8f>.3 
 
 8 
 
 393.8 
 
 2 
 
 433.3 
 
 6 
 
 472.8 
 
 7 
 
 275.9 
 
 1 
 
 315.4 
 
 5 
 
 854.9 
 
 9 
 
 394.4 
 
 3 
 
 483 9 
 
 7 
 
 473.4 
 
 8 
 
 276.5 
 
 2 
 
 816.0 
 
 6 
 
 355.5 
 
 640 
 
 395.0 
 
 4 
 
 434.6 
 
 8 
 
 474.1 
 
164 
 
 PRINCIPLES AND PRACTICE OF 
 
 AUXILIARY TO TABLE IV. 
 
 WHEN THE AREAS CONTAIN DECIMAL PARTS. 
 
 Decimal of Areas. 
 
 Decimal 
 Cubic Yards 
 Corresponding. 
 
 .00 
 
 .0 
 
 .17 
 
 .1 
 
 .33 
 
 .2 
 
 .50 
 
 .3 
 
 .66 
 
 A 
 
 .83 
 
 5 
 
 1.00 
 
 .6 
 
 N.B. When the square area consists of a whole number and of 
 decimal parts of a whole number, the cubic yards corresponding to those 
 decimal parts, as given in the subjoined Auxiliary Table, are to be added 
 to the cubic yards corresponding to the whole number as set forth in 
 Table IV. 
 
EMBANKING LANDS FEOM KIVER-FLOODS. 
 
 165 
 
 TABLE IV. (Continued.) 
 Table of Cubic Yards corresponding to Areas in square feet. 
 
 i 
 
 a* 
 
 
 
 g 
 
 B S 
 
 ~ 
 
 K fcO 
 
 ^ 3 
 
 3> 
 
 ^ 
 
 "S 
 
 fci 
 
 
 
 a) ti 
 
 Areas 
 in square f 
 
 Cubic yai 
 correspond; 
 
 Areas 
 in squaie f 
 
 ! 
 
 ^3 
 
 
 5 I 
 
 i " 
 
 % 
 
 G 
 
 II 
 
 6 o 
 
 Areas 
 in square f 
 
 Cubic yai 
 correspond 
 
 Areas 
 in square f 
 
 Cubic yar 
 correspond 
 
 2 
 
 *f 
 
 _a 
 
 Cubic yai 
 correspond 
 
 9 
 
 474.7 
 
 3 
 
 514.2 
 
 1 
 
 553.7 
 
 1 
 
 593.2 
 
 5 
 
 632.7 
 
 9 
 
 672.2 
 
 770 
 
 475.3 
 
 4 
 
 514.8 
 
 8 
 
 554.3 
 
 2 
 
 593.8 
 
 6 
 
 633.3 
 
 1090 
 
 672.8 
 
 1 
 
 475.9 
 
 5 
 
 515.4 
 
 9 
 
 554.9 
 
 3 
 
 594.4 
 
 7 
 
 633.9 
 
 1 
 
 673.5 
 
 2 
 
 476.5 
 
 6 
 
 516.0 
 
 900 
 
 555.5 
 
 4 
 
 595.1 
 
 8 
 
 634.6 
 
 2 
 
 674.1 
 
 3 
 
 477.1 
 
 7 
 
 516.7 
 
 1 
 
 556.2 
 
 5 
 
 595.7 
 
 9 
 
 635.2 
 
 3 
 
 674.7 
 
 4 
 
 477.8 
 
 8 
 
 517.3 
 
 2 
 
 556.8 
 
 6 
 
 596.3 
 
 1030 
 
 635.8 
 
 4 
 
 675.3 
 
 5 
 
 478.4 
 
 9 
 
 517.9 
 
 3 
 
 557.4 
 
 7 
 
 596.9 
 
 1 
 
 636.4 
 
 5 
 
 675.9 
 
 6 
 
 479.0 
 
 840 
 
 5185 
 
 4 
 
 558.0 
 
 8 
 
 597.5 
 
 2 
 
 637.0 
 
 6 
 
 676.5 
 
 7 
 
 479.6 
 
 1 
 
 519.1 
 
 5 
 
 553.6 
 
 9 
 
 598.1 
 
 8 
 
 637.7 
 
 7 
 
 677.2 
 
 8 
 
 480. 2 
 
 2 
 
 519.7 
 
 6 
 
 559.3 
 
 97O 
 
 598.8 
 
 4 
 
 638.3 
 
 8 
 
 677.8 
 
 9 
 
 480.8 
 
 3 
 
 520.4 
 
 7 
 
 559.9 
 
 1 
 
 599.4 
 
 5 
 
 638.9 
 
 9 
 
 678.4 
 
 78O 
 
 481.5 
 
 4 
 
 521.0 
 
 8 
 
 560.5 
 
 2 
 
 600.0 
 
 6 
 
 639.5 
 
 1100 
 
 679.0 
 
 1 
 
 482.1 
 
 5 
 
 521.6 
 
 9 
 
 561.1 
 
 3 
 
 600.6 
 
 7 
 
 640.1 
 
 1 
 
 679.6 
 
 2 
 
 4S2.7 
 
 6 
 
 522.2 
 
 910 
 
 561.7 
 
 4 
 
 601.2 
 
 8 
 
 640.7 
 
 2 
 
 680.2 
 
 8 
 
 483.3 
 
 7 
 
 522.8 
 
 1 
 
 562.3 
 
 5 
 
 601.8 
 
 9 
 
 641.4 
 
 3 
 
 680.9 
 
 4 
 
 483.9 
 
 8 
 
 523.4 
 
 2 
 
 563.0 
 
 6 
 
 602.5 
 
 1040 
 
 642.0 
 
 4 
 
 681.5 
 
 5 
 
 484.5 
 
 9 
 
 524.1 
 
 3 
 
 563.6 
 
 7 
 
 603.1 
 
 1 
 
 642.6 
 
 5 
 
 682.1 
 
 6 
 
 485.2 
 
 85O 
 
 52i.7 
 
 4 
 
 5C4.2 
 
 8- 
 
 603.7 
 
 2 
 
 643.2 
 
 6 
 
 682.7 
 
 7 
 
 485.8 
 
 1 
 
 525.3 
 
 5 
 
 564.8 
 
 9 
 
 604.3 
 
 3 
 
 643.8 
 
 7 
 
 683.3 
 
 8 
 
 486.4 
 
 2 
 
 525.9 
 
 6 
 
 565.4 
 
 980 
 
 604.9 
 
 4 
 
 644.4 
 
 8 
 
 683.9 
 
 9 
 
 487.0 
 
 3 
 
 526.5 
 
 7 
 
 566.0 
 
 1 
 
 605.5 
 
 5 
 
 645.1 
 
 9 
 
 684.6 
 
 79O 
 
 487. 
 
 4 
 
 527.1 
 
 8 
 
 566.7 
 
 2 
 
 606.2 
 
 6 
 
 645.7 
 
 1110 
 
 685.2 
 
 1 
 
 4S8.2 
 
 5 
 
 527.8 
 
 9 
 
 567.3 
 
 3 
 
 606.8 
 
 7 
 
 646.3 
 
 1 
 
 685.8 
 
 2 
 
 488.9 
 
 6 
 
 528.4 
 
 920 
 
 567.9 
 
 4 
 
 607.4 
 
 8 
 
 646.9 
 
 2 
 
 686.4 
 
 3 
 
 489.5 
 
 7 
 
 529.0 
 
 1 
 
 568.5 
 
 5 
 
 608.0 
 
 9 
 
 647.5 
 
 3 
 
 687.0 
 
 4 
 
 400.1 
 
 8 
 
 529.6 
 
 2 
 
 569.1 
 
 6 
 
 608.6 
 
 1050 
 
 648.1 
 
 4 
 
 687.7 
 
 5 
 
 490.7 
 
 9 
 
 530.2 
 
 3 
 
 569.7 
 
 7 
 
 609.3 
 
 i 
 
 648.8 
 
 5 
 
 688.3 
 
 6 
 
 491.4 
 
 860 
 
 530.8 
 
 4 
 
 570.4 
 
 8 
 
 609.9 
 
 2 
 
 649.4 
 
 6 
 
 688.9 
 
 7 
 
 492.0 
 
 1 
 
 531.5 
 
 5 
 
 571.0 
 
 9 
 
 610.5 
 
 3 
 
 650.0 
 
 7 
 
 689.5 
 
 8 
 
 492.0 
 
 2 
 
 532.1 
 
 6 
 
 571.6 
 
 99O 
 
 611.1 
 
 4 
 
 650.6 
 
 8 
 
 690.1 
 
 9 
 
 493.2 
 
 8 
 
 5327 
 
 7 
 
 572.2 
 
 1 
 
 611.7 
 
 5 
 
 651.2 
 
 9 
 
 690.7 
 
 80O 
 
 493.8 
 
 4 
 
 533.3 
 
 8 
 
 572.8 
 
 
 612.3 
 
 6 
 
 '651.8 
 
 1120 
 
 691.4 
 
 1 
 
 494.4 
 
 5 
 
 533.9 
 
 9 
 
 573.4 
 
 3 
 
 613.0 
 
 7 
 
 652.5 
 
 1 
 
 692.0 
 
 2 
 
 495.1 
 
 6 
 
 534.5 
 
 930 
 
 574.1 
 
 4 
 
 613.6 
 
 8 
 
 653.1 
 
 2 
 
 692.6 
 
 3 
 
 495.7 
 
 7 
 
 535.2 
 
 1 
 
 574.7 
 
 5 
 
 614.2 
 
 9 
 
 653.7 
 
 8 
 
 693.2 
 
 4 
 
 496.3 
 
 8 
 
 535.8 
 
 2 
 
 575.3 
 
 6 
 
 614.8 
 
 11060 
 
 654.3 
 
 4 
 
 693.8 
 
 5 
 
 496.9 
 
 9 
 
 536.4 
 
 3 
 
 575.9 
 
 7 
 
 615.4' 
 
 1 
 
 654.9 
 
 5 
 
 694.4 
 
 6 
 
 497.5 
 
 87O 
 
 537.0 
 
 4 
 
 576.5 
 
 8 
 
 616.0 
 
 2 
 
 655.5 
 
 6 
 
 695.1 
 
 
 498.1 
 
 1 
 
 5376 
 
 5 
 
 577.1 
 
 9 
 
 616.7 
 
 3 
 
 656.2 
 
 7 
 
 695.7 
 
 8 
 
 498.8 
 
 2 
 
 538.3 
 
 6 
 
 577.8 
 
 1000 
 
 617.3 
 
 4 
 
 656.8 
 
 8 
 
 696.3 
 
 9 
 
 499.4 
 
 3 
 
 538.9 
 
 7 
 
 578.4 
 
 1 
 
 617.9 
 
 5 
 
 657.4 
 
 9 
 
 696.9 
 
 81O 
 
 500.0 
 
 4 
 
 539.5 
 
 8 
 
 579.0 
 
 2 
 
 618.5 
 
 6 
 
 658.0 
 
 113O 
 
 697.5 
 
 1 
 
 500.6 
 
 5 
 
 540.1 
 
 9 
 
 579.6 
 
 3 
 
 619.1 
 
 7 
 
 658.6 
 
 1 
 
 698.1 
 
 2 
 
 501.2 
 
 6 
 
 5407 
 
 94O 
 
 5S0.2 
 
 4 
 
 619.8 
 
 8 
 
 659.3 
 
 2 
 
 698.8 
 
 3 
 
 501.8 
 
 7 
 
 541.4 
 
 1 
 
 580.8 
 
 5 
 
 620.4 
 
 9 
 
 659.9 
 
 3 
 
 699.4 
 
 4 
 
 502.5 
 
 8 
 
 5420 
 
 2 
 
 581.5 
 
 6 
 
 621.0 
 
 107O 
 
 660.5 
 
 4 
 
 700.0 
 
 5 
 
 503.1 
 
 9 
 
 542.6 
 
 3 
 
 582.1 
 
 7 
 
 621.6 
 
 1 
 
 661.1 
 
 5 
 
 700.6 
 
 6 
 
 503.7 
 
 8SO 
 
 543.2 
 
 4 
 
 5S2.7 
 
 8 
 
 622.2 
 
 2 
 
 661.7 
 
 6 
 
 701.2 
 
 7 
 
 504.3 
 
 1 
 
 5438 
 
 5 
 
 5S3.3 
 
 9 
 
 622.8 
 
 3 
 
 662.3 
 
 7 
 
 701.8 
 
 8 
 
 504.9 
 
 2 
 
 54M 
 
 6 
 
 5S3.9 
 
 1O1O 
 
 623.5 
 
 4 
 
 663.0 
 
 8 
 
 702.5 
 
 9 
 
 505.5 
 
 3 
 
 545.1 
 
 7 
 
 584.5 
 
 1 
 
 624.1 
 
 5 
 
 663.6 
 
 9 
 
 703.1 
 
 82O 
 
 506.2 
 
 4 
 
 5457 
 
 8 
 
 585.2 
 
 2 
 
 624.7 
 
 6 
 
 664.2 
 
 114O 
 
 703.7 
 
 1 
 
 506.8 
 
 5 
 
 546.3 
 
 9 
 
 585.8 
 
 3 
 
 625.3 
 
 7 
 
 664.8 
 
 1 
 
 704.3 
 
 2 
 
 507.4 
 
 6 
 
 5469 
 
 95O 
 
 586.4 
 
 4 
 
 625.9 
 
 8 
 
 665.4 
 
 2 
 
 704.9 
 
 3 
 
 508.0 
 
 7 
 
 5475 
 
 1 
 
 587.0 
 
 5 
 
 626.5 
 
 9 
 
 666.0 
 
 3 
 
 7055 
 
 4 
 
 508.6 
 
 8 
 
 548.1 
 
 2 
 
 537.6 
 
 6 
 
 627.2 
 
 180O 
 
 666.7 
 
 4 
 
 706.2 
 
 5 
 
 509.2 
 
 9 
 
 548.8 
 
 3 
 
 58S.3 
 
 7 
 
 627.8 
 
 1 
 
 667.3 
 
 5 
 
 706.8 
 
 6 
 
 509.9 
 
 890 
 
 549.4 
 
 4 
 
 5S3.9 
 
 8 
 
 628.4 
 
 2 
 
 667.9 
 
 6 
 
 707.4 
 
 7 
 
 510.5 
 
 1 
 
 550.0 
 
 5 
 
 589.5 
 
 9 
 
 629.0 
 
 8 
 
 668.5 
 
 7 
 
 70S.O 
 
 8 
 
 511.1 
 
 2 
 
 5506 
 
 6 
 
 590.1 
 
 1O20 
 
 629.6 
 
 4 
 
 669.1 
 
 8 
 
 708.6 
 
 9 
 
 511.7 
 
 3 
 
 5512 
 
 7 
 
 5907 
 
 1 
 
 680.2 
 
 5 
 
 669.8 
 
 9 
 
 709.3 
 
 83O 
 
 512.3 
 
 4 
 
 55ll8 
 
 8 
 
 591.4 
 
 2 
 
 630.9 
 
 6 
 
 670.4 
 
 115O 
 
 709.9 
 
 1 
 
 513.0 
 
 5 
 
 552 5 
 
 9 
 
 592.0 
 
 3 
 
 631.5 
 
 7 
 
 671.0 
 
 1 
 
 710.5 
 
 2 
 
 513.6 
 
 6 
 
 553.1 
 
 960 
 
 592.6 
 
 4 
 
 632.1 
 
 8 
 
 671.6 
 
 2 
 
 711.1 
 
166 
 
 PRINCIPLES AND PKACTICE OF 
 
 AUXILIARY TO TABLE IV. 
 
 WHEN THE AREAS CONTAIN DECIMAL PARTS. 
 
 Decimal of Areas. 
 
 Decimal 
 Cubic Yards 
 Corresponding. 
 
 .00 
 
 .0 
 
 .17 
 
 .1 
 
 .33 
 
 .2 
 
 .50 
 
 .3 
 
 .66 
 
 .4 
 
 .83 
 
 .6 
 
 1.00 
 
 .6 
 
 N.B. 'When the square area consists of a whole number and of 
 decimal parts of a whole number, the cubic yards corresponding to those 
 decimal parts, as given in the subjoined Auxiliary Table, are to be added 
 to the cubic yards corresponding to the whole number as set forth in 
 Table IV. 
 
PRINCIPLES AND PRACTICE OF 
 
 167 
 
 TABLE TV. (Continued.) 
 Table of Cubic Yards corresponding to Areas in square feet. 
 
 ll 
 
 fci 
 
 11 
 
 1 
 
 Sjj 
 fcf 
 
 1 
 1 2 
 
 si 
 
 S. s 
 
 *" -3 
 
 J 
 
 i 
 
 m M 
 
 *" 'S 
 
 i 
 
 w fcJb 
 
 J 
 
 2 
 
 ft 
 
 *| 
 
 o'g. 
 
 *| 
 
 o ft 
 
 si 
 
 *t 
 
 ll 
 
 
 ll 
 
 *f 
 
 l| 
 
 "^1 
 
 ll 
 
 1 
 
 8 
 
 g 
 
 u 
 
 S 
 
 s 
 
 .2 
 
 8 
 
 .9 
 
 s 
 
 .9 
 
 8 
 
 3 
 
 711.7 
 
 7 
 
 751.2 
 
 1 
 
 790.7 
 
 5 
 
 830.2 
 
 9 
 
 869.8 
 
 8 
 
 909.3 
 
 4 
 
 712.3 
 
 8 
 
 751.8 
 
 2 
 
 791.4 
 
 6 
 
 830.9 
 
 1410 
 
 870-4 
 
 4 
 
 909.9 
 
 5 
 
 713.0 
 
 9 
 
 752.5 
 
 3 
 
 792.0 
 
 7 
 
 831.5 
 
 1 
 
 871-0 
 
 5 
 
 910.5 
 
 6 
 
 713.6 
 
 1220 
 
 753.1 
 
 4 
 
 792.6 
 
 8 
 
 832.1 
 
 2 
 
 871-6 
 
 6 
 
 911.1 
 
 7 
 
 714.2 
 
 1 
 
 753.7 
 
 5 
 
 793.2 
 
 9 
 
 832.7 
 
 3 
 
 872-2 
 
 7 
 
 911.7 
 
 8 
 
 714.8 
 
 2 
 
 754.3 
 
 6 
 
 793.8 
 
 1350 
 
 833.3 
 
 4 
 
 872-8 
 
 8 
 
 912.3 
 
 9 
 
 715.4 
 
 3 
 
 754.9 
 
 7 
 
 794.4 
 
 1 
 
 833.9 
 
 5 
 
 873-5 
 
 9 
 
 913.0 
 
 116O 
 
 716.0 
 
 4 
 
 755.5 
 
 8 
 
 795.1 
 
 2 
 
 834.6 
 
 6 
 
 874-1 
 
 1480 
 
 913.6 
 
 1 
 
 716.7 
 
 5 
 
 756.2 
 
 9 
 
 795.7 
 
 3 
 
 835.2 
 
 7 
 
 874-7 
 
 1 
 
 914.2 
 
 2 
 
 717.3 
 
 6 
 
 756.8 
 
 129O 
 
 796.3 
 
 4 
 
 835.8 
 
 8 
 
 875-3 
 
 2 
 
 914.8 
 
 3 
 
 717.9 
 
 7 
 
 757.4 
 
 1 
 
 796.9 
 
 5 
 
 836.4 
 
 9 
 
 875-9 
 
 3 
 
 915.4 
 
 4 
 
 718.5 
 
 8 
 
 758.0 
 
 2 
 
 797.5 
 
 6 
 
 837.0 
 
 1420 
 
 876-5 
 
 4 
 
 916.0 
 
 5 
 
 719.1 
 
 9 
 
 758.6 
 
 3 
 
 798.1 
 
 7 
 
 837.7 
 
 1 
 
 877-2 
 
 5 
 
 916.7 
 
 6 
 
 719.8 
 
 1230 
 
 759.3 
 
 4 
 
 798.8 
 
 8 
 
 838.3 
 
 2 
 
 877-8 
 
 6 
 
 917.3 
 
 7 
 
 720.4 
 
 1 
 
 759.9 
 
 5 
 
 799.4 
 
 9 
 
 838.9 
 
 3 
 
 878-4 
 
 7 
 
 917.9 
 
 8 
 
 721.0 
 
 2 
 
 760.5 
 
 6 
 
 800.0 
 
 1360 
 
 839.5 
 
 4 
 
 879-0 
 
 8 
 
 918.5 
 
 9 
 
 721.6 
 
 3 
 
 761.1 
 
 7 
 
 800.6 
 
 1 
 
 840.1 
 
 5 
 
 879-6 
 
 9 
 
 919.1 
 
 1170 
 
 722.2 
 
 4 
 
 761.7 
 
 8 
 
 801.2 
 
 2 
 
 840.7 
 
 6 
 
 880-2 
 
 1490 
 
 919.8 
 
 1 
 
 722.8 
 
 5 
 
 762.3 
 
 9 
 
 801.8 
 
 3 
 
 841.4 
 
 7 
 
 880-9 
 
 1 
 
 920.4 
 
 2 
 
 723.5 
 
 6 
 
 763.0 
 
 1300 
 
 802.5 
 
 4 
 
 842.0 
 
 8 
 
 881-5 
 
 2 
 
 921.0 
 
 3 
 
 724.1 
 
 7 
 
 763.6 
 
 1 
 
 803.1 
 
 5 
 
 842,6 
 
 9 
 
 882-1 
 
 3 
 
 921.6 
 
 4 
 
 724.7 
 
 8 
 
 764.2 
 
 2 
 
 . 803.7 
 
 6 
 
 843.2 
 
 143O 
 
 882-7 
 
 4 
 
 922.2 
 
 5 
 
 725.3 
 
 9 
 
 764.8 
 
 3 
 
 804.3 
 
 7 
 
 843.8 
 
 1 
 
 883-3 
 
 5 
 
 922.8 
 
 6 
 
 725.9 
 
 1240 
 
 765.4 
 
 4 
 
 804.9 
 
 8 
 
 844.4 
 
 2 
 
 883-9 
 
 6 
 
 923.5 
 
 7 
 
 726.5 
 
 1 
 
 766.0 
 
 5 
 
 805.5 
 
 9 
 
 845.1 
 
 3 
 
 884-6 
 
 7 
 
 924.1 
 
 8 
 
 727.2 
 
 2 
 
 766.7 
 
 6 
 
 806.2 
 
 1370 
 
 845.7 
 
 4 
 
 885-2 
 
 8 
 
 924.7 
 
 9 
 
 727.8 
 
 3 
 
 767.3 
 
 7 
 
 806.8 
 
 1 
 
 846.3 
 
 5 
 
 885-8 
 
 9 
 
 925.3 
 
 1180 
 
 728.4 
 
 4 
 
 767.9 
 
 8 
 
 807.4 
 
 2 
 
 846.9 
 
 6 
 
 886-4 
 
 1500 
 
 925.9 
 
 1 
 
 729.0 
 
 6 
 
 768.5 
 
 9 
 
 808.0 
 
 3 
 
 847.5 
 
 7 
 
 887-0 
 
 1 
 
 926.5 
 
 2 
 
 729.6 
 
 6 
 
 769.1 
 
 1310 
 
 808.6 
 
 4 
 
 848.1 
 
 8 
 
 887-7 
 
 2 
 
 927!2 
 
 8 
 
 730.2 
 
 7 
 
 769.8 
 
 1 
 
 809.3 
 
 5 
 
 848.8 
 
 9 
 
 888-3 
 
 3 
 
 927.8 
 
 4 
 
 730.9 
 
 8 
 
 770.4 
 
 2 
 
 809.9 
 
 6 
 
 849.4 
 
 144O 
 
 888-9 
 
 4 
 
 928.4 
 
 5 
 
 731.5 
 
 9 
 
 771.0 
 
 8 
 
 810.5 
 
 7 
 
 850.0 
 
 1 
 
 889-5 
 
 5 
 
 929.0 
 
 6 
 
 732.1 
 
 1250 
 
 771.6 
 
 4 
 
 811.1 
 
 8 
 
 850.6 
 
 2 
 
 890-1 
 
 6 
 
 929.6 
 
 7 
 
 732.7 
 
 1 
 
 772.2 
 
 5 
 
 811.7 
 
 9 
 
 851.2 
 
 3 
 
 890-7 
 
 7 
 
 930.2 
 
 8 
 
 733.3 
 
 2 
 
 7728 
 
 6 
 
 812.3 
 
 138O 
 
 851.8 
 
 4 
 
 891-4 
 
 8 
 
 930.9 
 
 9 
 
 733.9 
 
 3 
 
 773.5 
 
 7 
 
 813.0 
 
 1 
 
 852.5 
 
 5 
 
 892-0 
 
 9 
 
 931.5 
 
 119O 
 
 734.6 
 
 4 
 
 774.1 
 
 8 
 
 813.6 
 
 2 
 
 853.1 
 
 6 
 
 892-6 
 
 1510 
 
 932.1 
 
 1 
 
 735.2 
 
 5 
 
 774.7 
 
 9 
 
 814.2 
 
 3 
 
 853.7 
 
 7 
 
 893-2 
 
 1 
 
 932.7 
 
 2 
 
 735.8 
 
 6 
 
 775.3 
 
 1320 
 
 814.8 
 
 4 
 
 854.3 
 
 8 
 
 893-8 
 
 2 
 
 933.3 
 
 3 
 
 736.4 
 
 7 
 
 775.9 
 
 1 
 
 815.4 
 
 5 
 
 854.9 
 
 9 
 
 894-4 
 
 3 
 
 938.9 
 
 4 
 
 737.0 
 
 8 
 
 776.5 
 
 2 
 
 816.0 
 
 6 
 
 855:5 
 
 145O 
 
 895-1 
 
 4 
 
 934.6 
 
 5 
 
 737.7 
 
 9 
 
 777.2 
 
 3 
 
 816.7 
 
 7 
 
 856.2 
 
 1 
 
 895-7 
 
 5 
 
 935.2 
 
 6 
 
 738.3 
 
 1260 
 
 777.8 
 
 4 
 
 817.3 
 
 8 
 
 856.8 
 
 2 
 
 896-3 
 
 6 
 
 935.8 
 
 7 
 
 738.9 
 
 1 
 
 778.4 
 
 5 
 
 817.9 
 
 9 
 
 857.4 
 
 3 
 
 896-9 
 
 7 
 
 936.4 
 
 8 
 
 739.5 
 
 2 
 
 779.0 
 
 6 
 
 818.5 
 
 1390 
 
 858.0 
 
 4 
 
 897-5 
 
 8 
 
 937.0 
 
 9 
 
 740.1 
 
 8 
 
 779.6 
 
 7 
 
 819.1 
 
 1 
 
 858.6 
 
 5 
 
 898-1 
 
 9 
 
 937.7 
 
 1200 
 
 740.7 
 
 4 
 
 7S0.2 
 
 8 
 
 819.8 
 
 2 
 
 859.3 
 
 6 
 
 898-8 
 
 1520 
 
 938.3 
 
 1 
 
 741.4 
 
 5 
 
 780.9 
 
 9 
 
 820.4 
 
 3 
 
 859.9 
 
 7 
 
 899-4 
 
 1 
 
 938.9 
 
 2 
 
 742.0 
 
 6 
 
 781.5 
 
 1330 
 
 821.0 
 
 4 
 
 860.5 
 
 8 
 
 900-0 
 
 2 
 
 939.5 
 
 3 
 
 742.6 
 
 7 
 
 7821 
 
 1 
 
 821.6 
 
 5 
 
 861.1 
 
 9 
 
 900-6 
 
 3 
 
 940.1 
 
 4 
 
 743.2 
 
 8 
 
 7S2.7 
 
 2 
 
 822.2 
 
 6 
 
 861.7 
 
 1460 
 
 901-2 
 
 4 
 
 940.T 
 
 5 
 
 743.8 
 
 9 
 
 783.3 
 
 3 
 
 822.8 
 
 7 
 
 862.3 
 
 1 
 
 901-8 
 
 5 
 
 941.4 
 
 6 
 
 744.4 
 
 1270 
 
 783.9 
 
 4 
 
 823.5 
 
 8 
 
 863.0 
 
 2 
 
 902-5 
 
 6 
 
 942.0 
 
 7 
 
 745.1 
 
 1 
 
 784.6 
 
 5 
 
 824.1 
 
 9 
 
 863.6 
 
 3 
 
 903-1 
 
 7 
 
 942.6 
 
 8 
 
 745.7 
 
 2 
 
 785.2 
 
 6 
 
 824.7 
 
 1400 
 
 864.2 
 
 4 
 
 903-7 
 
 8 
 
 943.2 
 
 9 
 
 746.3 
 
 3 
 
 785.8 
 
 7 
 
 825.3 
 
 1 
 
 864.8 
 
 5 
 
 904-3 
 
 9 
 
 948.8 
 
 112O 
 
 746.9 
 
 4 
 
 7S6.4 
 
 8 
 
 825.9 
 
 2 
 
 865.4 
 
 6 
 
 904-9 
 
 1530 
 
 944.4 
 
 1 
 
 747.5 
 
 5 
 
 7-7.0 
 
 9 
 
 826.5 
 
 3 
 
 866.0 
 
 7 
 
 905-5 
 
 1 
 
 945.1 
 
 2 
 
 748.1 
 
 6 
 
 787.7 
 
 134O 
 
 827.2 
 
 4 
 
 860.7 
 
 8 
 
 906-2 
 
 2 
 
 945.7 
 
 8 
 
 748.8 
 
 7 
 
 788.3 
 
 1 
 
 827.8 
 
 5 
 
 867.3 
 
 9 
 
 906.8 
 
 3 
 
 946.3 
 
 4 
 
 749.4 
 
 8 
 
 788.9 
 
 2 
 
 828.4 
 
 6 
 
 867.9 
 
 147O 
 
 907.4 
 
 4 
 
 946.9 
 
 5 
 
 750.0 
 
 9 
 
 789.5 
 
 3 
 
 829.0 
 
 7 
 
 868.5 
 
 1 
 
 908.0 
 
 5 
 
 947.5 
 
 6 
 
 750-6 
 
 1280 
 
 790.1 
 
 4 
 
 829.6 
 
 8 
 
 869.1 
 
 2 
 
 &03.6 
 
 6 
 
 948.1 
 
168 
 
 PKIXCIPLES AND PRACTICE OF 
 
 AUXILIARY TO TABLE IV. 
 
 WHEN THE AREAS CONTAIN DECIMAL PAIITS. 
 
 Decimal of Areas. 
 
 Decimal 
 Cubic Yards 
 Corresponding. 
 
 .00 
 
 .0 
 
 .17 
 
 .1 
 
 .33 
 
 .2 
 
 .50 
 
 .3 
 
 .66 
 
 .4 
 
 .83 
 
 .5 
 
 1.00 
 
 .6 
 
 N.B. When the square area consists of a whole number aud of 
 decimal parts of a whole number, the cubic yards corresponding to those 
 decimal parts, as given in the subjoined Auxiliary Table, are to be added 
 to the cubic yards corresponding to the whole number as set forth in 
 Table IV. 
 
EMBANKING LANDS FEOM EIVER-FLOODS. 
 
 169 
 
 TABLE TV. (Continued.) 
 Table of Cubic Yards corresponding to Areas in square feet. 
 
 ts 
 
 .si 
 
 1 
 
 0) **> 
 
 A 
 
 ii 
 
 1 
 
 |I 
 
 "o 
 
 il 
 
 I 
 
 ll 
 
 DC* 1 "* 
 
 5 ^ 
 
 K^ 
 
 ?"a 
 
 
 5 a 
 
 1 2 
 
 fcl 
 
 S g 
 
 fefl 
 
 < 
 
 ^"q 
 
 Ji 
 
 si 
 
 <! 
 
 2 CO 
 
 s,i 
 
 II 
 
 
 
 II 
 
 ll 
 
 51 
 
 ll 
 
 .s 
 
 5 8 
 
 A 
 
 6 i 
 
 a 
 
 6 8 
 
 .a 
 
 ^8 
 
 .s 
 
 6 8 
 
 a 
 
 S 
 
 f" 
 
 948.8 
 
 1 
 
 988.3 
 
 5~ 
 
 1027.8 
 
 <T 
 
 1067.3 
 
 3 
 
 1106.8 
 
 7 
 
 U4g g 
 
 8 
 
 949.4 
 
 2 
 
 988.9 
 
 6 
 
 1028.4 
 
 1730 
 
 1067.9 
 
 4 
 
 1107.4 
 
 8 
 
 114&9 
 
 9 
 
 950.0 
 
 3 
 
 9S9.5 
 
 7 
 
 1029.0 
 
 1 
 
 1068.9 
 
 5 
 
 1108.0 
 
 9 
 
 1147.5 
 
 154O 
 
 950.6 
 
 4 
 
 990.1 
 
 8 
 
 1029.6 
 
 2 
 
 1069.1 
 
 6 
 
 1108.6 
 
 1860 
 
 1148.1 
 
 1 
 
 951.2 
 
 5 
 
 990.7 
 
 9 
 
 1030.2 
 
 8 
 
 1069.8 
 
 7 
 
 1109.3 
 
 1 
 
 1148.8 
 
 2 
 
 951.8 
 
 6 
 
 991.4 
 
 1670 
 
 1030.9 
 
 4 
 
 1070.4 
 
 8 
 
 1109.9 
 
 2 
 
 1149.4 
 
 3 
 
 952.5 
 
 7 
 
 992.0- 
 
 1 
 
 1031.5 
 
 5 
 
 1071.0 
 
 9 
 
 1110.5 
 
 3 
 
 1150.0 
 
 4 
 
 953.1 
 
 8 
 
 992.6 
 
 2 
 
 1032.1 
 
 6 
 
 1071.6 
 
 180O 
 
 1111.1 
 
 4 
 
 1150.6 
 
 5 
 
 953.7 
 
 9 
 
 993.2 
 
 3 
 
 1032.7 
 
 7 
 
 1072.2 
 
 1 
 
 1111.7 
 
 5 
 
 1151.2 
 
 6 
 
 954.3 
 
 161O 
 
 993.8 
 
 4 
 
 1033.3 
 
 8 
 
 1072.8 
 
 2 
 
 1112.3 
 
 6 
 
 1151.8 
 
 7 
 
 954.9 
 
 1 
 
 994.4 
 
 5 
 
 1033.9 
 
 9 
 
 1073.5 
 
 8 
 
 1118.0 
 
 7 
 
 1152.5 
 
 8 
 
 955.5 
 
 2 
 
 995.1 
 
 6 
 
 1034.6 
 
 1740 
 
 1074.1 
 
 4 
 
 1113.6 
 
 8 
 
 1153.1 
 
 9 
 
 956.2 
 
 3 
 
 995.7 
 
 7 
 
 1035.2 
 
 1 
 
 1074.7 
 
 5 
 
 1114.2 
 
 9 
 
 1153.7 
 
 155O 
 
 956.8 
 
 4 
 
 996.3 
 
 8 
 
 1035.8 
 
 2 
 
 1075.8 
 
 6 
 
 1114.8 
 
 1870 
 
 1154.3 
 
 1 
 
 957.4 
 
 5 
 
 996.9 
 
 9 
 
 1036.4 
 
 3 
 
 1075.9 
 
 7 
 
 1115.4 
 
 1 
 
 1154.9 
 
 2 
 
 958.0 
 
 6 
 
 997.5 
 
 168O 
 
 1037.0 
 
 4 
 
 1076.5 
 
 8 
 
 1116.0 
 
 2 
 
 1155.5 
 
 3 
 
 958.6 
 
 7 
 
 998.1 
 
 1 
 
 1037.7 
 
 5 
 
 1077.2 
 
 9 
 
 1116.7 
 
 8 
 
 1156.2 
 
 4 
 
 959.8 
 
 8 
 
 998.8 
 
 2 
 
 1038.3 
 
 6 
 
 1077.8 
 
 181O 
 
 1117.8 
 
 4 
 
 1156.8 
 
 5 
 
 959.9 
 
 9 
 
 999.4 
 
 3 
 
 1038.9 
 
 7 
 
 1078.4 
 
 1 
 
 1117.9 
 
 5 
 
 1157.4 
 
 6 
 
 960.5 
 
 1620 
 
 1000.0 
 
 4 
 
 1039.5 
 
 8 
 
 1079.0 
 
 2 
 
 1118-5 
 
 6 
 
 1158.0 
 
 7 
 
 961.1 
 
 1 
 
 1000.6 
 
 5 
 
 1040-1 
 
 9 
 
 1079.6 
 
 8 
 
 1119.1 
 
 7 
 
 1158.6 
 
 8 
 
 961.7 
 
 2 
 
 1001.2 
 
 6 
 
 1040-7 
 
 1750 
 
 10S0.2 
 
 4 
 
 1119.8 
 
 8 
 
 1159.3 
 
 9 
 
 962.3 
 
 3 
 
 1001.8 
 
 7 
 
 1041-4 
 
 1 
 
 1080.9 
 
 5 
 
 1120.4 
 
 9 
 
 1159.9 
 
 156O 
 
 963.0 
 
 4 
 
 1002.5 
 
 8 
 
 1042-0 
 
 2 
 
 1081-5 
 
 6 
 
 1121.0 
 
 1880 
 
 1160.5 
 
 1 
 
 963.6 
 
 5 
 
 1003.1 
 
 9 
 
 1042-6 
 
 3 
 
 1082-1 
 
 7 
 
 1121.6 
 
 1 
 
 1161.1 
 
 2 
 
 964.2 
 
 6 
 
 1003.7 
 
 1690 
 
 1043-2 
 
 4 
 
 1082-7 
 
 8 
 
 1122.2 
 
 2 
 
 1161.7 
 
 3 
 
 964.8 
 
 7 
 
 1004.3 
 
 1 
 
 1043-8 
 
 5 
 
 1083.3 
 
 9 
 
 1122.8 
 
 8 
 
 1162.3 
 
 4 
 
 965.4 
 
 8 
 
 1004.9 
 
 2 
 
 1044-4 
 
 6 
 
 1083.9 
 
 1820 
 
 1123.5 
 
 4 
 
 1163.0 
 
 5 
 
 966.0 
 
 9 
 
 1005.5 
 
 3 
 
 1045-1 
 
 7 
 
 1084.6 
 
 1 
 
 1124.1 
 
 5 
 
 1163.6 
 
 6 
 
 9667 
 
 163O 
 
 1006.2 
 
 4 
 
 1045-7 
 
 8 
 
 1085.2 
 
 2 
 
 1124.7 
 
 6 
 
 1164.2 
 
 7 
 
 967.3 
 
 1 
 
 1006.8 
 
 5 
 
 1046-3 
 
 9 
 
 1085-8 
 
 8 
 
 1125.3 
 
 7 
 
 1164.8 
 
 8 
 
 967.9 
 
 2 
 
 1007.4 
 
 6 
 
 1046-9 
 
 176O 
 
 1086.4 
 
 4 
 
 1125.9 
 
 8 
 
 1165.4 
 
 9 
 
 968.5 
 
 3 
 
 1008.0 
 
 
 1047-5 
 
 1 
 
 1087-0 
 
 5 
 
 1126.5 
 
 9 
 
 1166.0 
 
 157O 
 
 969.1 
 
 4 
 
 1003.6 
 
 8 
 
 1048-1 
 
 2 
 
 1087-7 
 
 6 
 
 1127.2 
 
 1890 
 
 1166.7 
 
 1 
 
 969.8 
 
 5 
 
 1009.3 
 
 9 
 
 1048-8 
 
 3 
 
 1088-3 
 
 7 
 
 1127.8 
 
 1 
 
 1167.3 
 
 2 
 
 970.4 
 
 6 
 
 1009.9 
 
 1700 
 
 1049-4 
 
 4 
 
 10S8-9 
 
 8 
 
 1128.4 
 
 2 
 
 1167.9 
 
 8 
 
 971.0 
 
 7 
 
 1010.5 
 
 1 
 
 1050-0 
 
 5 
 
 1089-5 
 
 9 
 
 1129.0 
 
 3 
 
 1168.5 
 
 4 
 
 971.6 
 
 8 
 
 1011.1 
 
 2 
 
 1050-6 
 
 6 
 
 1090-1 
 
 1830 
 
 1129.6 
 
 4 
 
 1169.1 
 
 5 
 
 972.2 
 
 9 
 
 1011.7 
 
 3 
 
 1051-2 
 
 7 
 
 1090-7 
 
 1 
 
 1130.2 
 
 5 
 
 1169.8 
 
 6 
 
 972.8 
 
 164O 
 
 1012.3 
 
 4 
 
 1051-8 
 
 8 
 
 1091.4 
 
 2 
 
 1130.9 
 
 6 
 
 1170.4 
 
 7 
 
 978.5 
 
 1 
 
 1013.0 
 
 5 
 
 1052-5 
 
 9 
 
 1092.0 
 
 
 1131.5 
 
 7 
 
 1171.0 
 
 8 
 
 974.1 
 
 2 
 
 1013.6 
 
 6 
 
 1053-1 
 
 177O 
 
 1092.6 
 
 4 
 
 1132.1 
 
 8 
 
 1171.6 
 
 9 
 
 974.7 
 
 3 
 
 1014.2 
 
 7 
 
 1053-7 
 
 1 
 
 1093.2 
 
 5 
 
 1132.7 
 
 9 
 
 1172.2 
 
 158O 
 
 975.3 
 
 4 
 
 1014.8 
 
 8 
 
 1054-3 
 
 2 
 
 1093.8 
 
 6 
 
 1133.3 
 
 1900 
 
 1172.8 
 
 1 
 
 975.9 
 
 5 
 
 1015.4 
 
 9 
 
 1054.9 
 
 8 
 
 1094.4 
 
 7 
 
 1133-9 
 
 1 
 
 1173.5 
 
 2 
 
 976.5 
 
 6 
 
 1016.0 
 
 1710 
 
 1055-5 
 
 4 
 
 1095.1 
 
 8 
 
 1184.6 
 
 2 
 
 1174.1 
 
 8 
 
 977.2 
 
 7 
 
 1016.7 
 
 1 
 
 1056-2 
 
 5 
 
 1095.7 
 
 9 
 
 1135.2 
 
 8 
 
 1174.7 
 
 4 
 
 977.3 
 
 8 
 
 1017.3 
 
 2 
 
 1056-8 
 
 6 
 
 1096.3 
 
 184O 
 
 1135.8 
 
 4 
 
 1175.3 
 
 5 
 
 973.4 
 
 9 
 
 1017.9 
 
 3 
 
 1057-4 
 
 7 
 
 1096-9 
 
 1 
 
 1136.4 
 
 5 
 
 1175.9 
 
 6 
 
 979.0 
 
 165O 
 
 1018.5 
 
 4 
 
 1058-0 
 
 8 
 
 1097-5 
 
 2 
 
 1137.0 
 
 6 
 
 1176.5 
 
 7 
 
 979.6 
 
 1 
 
 1019.1 
 
 5 
 
 1058-6 
 
 9 
 
 1098.1 
 
 3 
 
 1137.7 
 
 7 
 
 1177.2 
 
 8 
 
 980.2 
 
 2 
 
 1019.8 
 
 6 
 
 1059-3 
 
 178O 
 
 1098.8 
 
 4 
 
 1138.3 
 
 8 
 
 1177.8 
 
 9 
 
 9S0.9 
 
 3 
 
 1020.4 
 
 7 
 
 1059-9 
 
 1 
 
 1099.4 
 
 5 
 
 1138.9 
 
 9 
 
 1178.4 
 
 159O 
 
 981.5 
 
 4 
 
 1021.0 
 
 8 
 
 1060-5 
 
 2 
 
 1100.0 
 
 6 
 
 1139.5 
 
 191O 
 
 1179.0 
 
 1 
 
 982.1 
 
 5 
 
 1021.6 
 
 9 
 
 1061.1 
 
 3 
 
 1100-6 
 
 7 
 
 1140.1 
 
 1 
 
 1179.6 
 
 2 
 
 982.7 
 
 6 
 
 1022.2 
 
 1720 
 
 1061-7 
 
 4 
 
 1101.2 
 
 8 
 
 1140.7 
 
 2 
 
 1180.2 
 
 3 
 
 9S3.3 
 
 7 
 
 1022.8 
 
 1 
 
 1062-3 
 
 5 
 
 1101.8 
 
 9 
 
 1141.4 
 
 8 
 
 1180.9 
 
 4 
 
 9S3.9 
 
 8 
 
 1023.5 
 
 2 
 
 1063.0 
 
 6 
 
 1102.5 
 
 185O 
 
 1142.0 
 
 4 
 
 1181.5 
 
 5 
 
 984.6 
 
 9 
 
 1024.1 
 
 3 
 
 1063.6 
 
 7 
 
 1103.1 
 
 1 
 
 1142.6 
 
 5 
 
 1182.1 
 
 o 
 
 985.2 
 
 166O 
 
 1024.7 
 
 4 
 
 1064.2 
 
 8 
 
 1103.7 
 
 2 
 
 1143.2 
 
 6 
 
 1182.7 
 
 7 
 
 935.8 
 
 1 
 
 1025.8 
 
 5 
 
 1064.8 
 
 9 
 
 1104.3 
 
 3 
 
 1143.8 
 
 7 
 
 1183.3 
 
 8 
 
 9S6.4 
 
 2 
 
 1025.9 
 
 6 
 
 1065.4 
 
 179O 
 
 1104.9 
 
 4 
 
 1144.4 
 
 8 
 
 1183.9 
 
 9 
 
 987.0 
 
 3 
 
 1026.5 
 
 7 
 
 1066.1 
 
 1 
 
 1105.5 
 
 5 
 
 1145.1 
 
 9 
 
 1184.6 
 
 160U 
 
 987.7 
 
 4 
 
 1027.2 
 
 8 
 
 1066.7 
 
 2 
 
 1106.2 
 
 6 
 
 1145.7 
 
 192O 
 
 1185.2 
 
170 
 
 PRINCIPLES AND PRACTICE OF 
 
 AUXILIARY TO TABLE IV. 
 
 WHEN THE AREAS CONTAIN DECIMAL PARTS. 
 
 Decimal of Areas. 
 
 Decimal 
 Cubic Yards 
 Corresponding. 
 
 .00 
 
 .0 
 
 .17 
 
 .1 
 
 .33 
 
 .2 
 
 .60 
 
 .3 
 
 .66 
 
 .4 
 
 .83 
 
 .6 
 
 1.00 
 
 .6 
 
 N.B. When the square area consists of a whole number and of 
 decimal parts of a whole number, the cubic yards corresponding to those 
 decimal parts, as given in the subjoined Auxiliary Table, are to be added 
 to the cubic yards corresponding to the whole number as set forth in 
 Table IY. 
 
PRINCIPLES AND PEACTICE OF 
 
 171 
 
 TABLE IV. (Continued.) 
 Table of Cubic Yards corresponding to Areas in square feet. 
 
 J 
 
 K k* 
 
 3 2 
 <=-a 
 
 J 
 
 to taO 
 
 o.S 
 13 
 
 s 
 
 a 
 
 tJo 
 
 rn ~ 
 
 1^ 
 
 1 
 
 1 
 
 1 
 
 tb 
 
 -S.S 
 
 1 
 
 gl 
 
 1| 
 *I 
 
 .5 
 
 Cubic ys 
 correspon 
 
 Areas 
 in square 
 
 Cubic yf 
 correspon 
 
 Area! 
 in square 
 
 1 
 
 11 
 
 s 
 
 B 0> 
 S 
 
 X | 
 
 .9 
 
 Cubic ys 
 correspou 
 
 5 
 <f 
 
 Cubic yf 
 correspou 
 
 Is 
 
 <! 
 
 Cubic yf 
 correspon 
 
 1 
 
 1185.8 
 
 2 
 
 1217.3 
 
 8 
 
 1248.8 
 
 4 
 
 1280.2 
 
 5 
 
 1311.7 
 
 e 
 
 1343.2 
 
 2 
 
 11S6.4 
 
 3 
 
 1217.9 
 
 4 
 
 1249.4 
 
 . 
 
 1280.9 
 
 6 
 
 1812.3 
 
 i 
 
 1343.8 
 
 3 
 
 1187.0 
 
 4 
 
 1218.5 
 
 5 
 
 1250.0 
 
 6 
 
 12S1.5 
 
 *j 
 
 1313.0 
 
 8 
 
 1344.4 
 
 4 
 
 1187.7 
 
 5 
 
 1219.1 
 
 6 
 
 1250.6 
 
 7 
 
 1282.1 
 
 8 
 
 1313.6 
 
 9 
 
 1345.1 
 
 5 
 
 1188.3 
 
 6 
 
 1219.8 
 
 7 
 
 1251.2 
 
 8 
 
 1282.7 
 
 9 
 
 1314.2 
 
 218O 
 
 1345.T 
 
 6 
 
 11SS.9 
 
 7 
 
 1220.4 
 
 8 
 
 1251.8 
 
 9 
 
 1283.3 
 
 2130 
 
 1314.8 
 
 1 
 
 1346.3 
 
 7 
 
 11S9.5 
 
 8 
 
 1221.0 
 
 9 
 
 1252.5 
 
 208O 
 
 1283.9 
 
 1 
 
 1315.4 
 
 2 
 
 1346.9 
 
 8 
 
 1190.1 
 
 9 
 
 1221.6 
 
 2030 
 
 1253.1 
 
 1 
 
 12S4.6 
 
 s 
 
 1316.0 
 
 3 
 
 1347.5 
 
 9 
 
 1190.7 
 
 198O 
 
 1222.2 
 
 1 
 
 1253.7 
 
 2 
 
 1285.2 
 
 3 
 
 1316.7 
 
 4 
 
 1348.1 
 
 193O 
 
 1191.4 
 
 1 
 
 1222.8 
 
 2 
 
 1254.3 
 
 3 
 
 1285.8 
 
 4 
 
 1317.3 
 
 5 
 
 1348.8 
 
 1 
 
 1192.0 
 
 2 
 
 1223.5 
 
 3 
 
 1254.9 
 
 4 
 
 1286.4 
 
 5 
 
 1317.9 
 
 6 
 
 1349.4 
 
 2 
 
 1192.6 
 
 8 
 
 1224.1 
 
 4 
 
 1255.6 
 
 5 
 
 1287.0 
 
 6 
 
 1318.5 
 
 7 
 
 1850.0 
 
 3 
 
 1193.2 
 
 4 
 
 1224.7 
 
 5 
 
 1256.2 
 
 6 
 
 1287.7 
 
 7 
 
 1319.1 
 
 8 
 
 1350.6 
 
 4 
 
 1193.8 
 
 5 
 
 1225.3 
 
 6 
 
 1256.8 
 
 7 
 
 128S.3 
 
 8 
 
 1319.8 
 
 9 
 
 1351.2 
 
 5 
 
 1194.4 
 
 6 
 
 1225.9 
 
 7 
 
 1257.4 
 
 8 
 
 1288.9 
 
 9 
 
 1320.4 
 
 219O 
 
 1351.8 
 
 6 
 
 1195.1 
 
 7 
 
 1226.5 
 
 8 
 
 1258.0 
 
 9 
 
 1289.5 
 
 2140 
 
 1321.0 
 
 1 
 
 1352.5 
 
 7 
 
 1195.7 
 
 8 
 
 1227.2 
 
 9 
 
 1258.6 
 
 2090 
 
 1290.1 
 
 1 
 
 1321.6 
 
 2 
 
 1353.1 
 
 8 
 
 1196.3 
 
 9 
 
 1227.8 
 
 204O 
 
 1259.3 
 
 1 
 
 129Q.7 
 
 2 
 
 1822.2 
 
 3 
 
 1353.7 
 
 9 
 
 1196.9 
 
 1990 
 
 1228.4 
 
 1 
 
 1259.9 
 
 2 
 
 1291.4 
 
 3 
 
 1322.8 
 
 4 
 
 1354.3 
 
 1940 
 
 1197,5 
 
 1 
 
 1229.0 
 
 2 
 
 1260.5 
 
 3 
 
 1292.0 
 
 4 
 
 1323.5 
 
 5 
 
 1354.9 
 
 1 
 
 1198.1 
 
 2 
 
 1229.6 
 
 8 
 
 1261.1 
 
 4 
 
 1292.6 
 
 5 
 
 1824.1 
 
 6 
 
 1355.6 
 
 2 
 
 1198.8 
 
 8 
 
 1230.2 
 
 4 
 
 1261.7 
 
 5 
 
 1293.2 
 
 6 
 
 1324.7 
 
 7 
 
 1356.2 
 
 8 
 
 1199.4 
 
 4 
 
 1230.9 
 
 5 
 
 1262.3 
 
 6 
 
 1293.8 
 
 7 
 
 1325.3 
 
 8 
 
 1356.8 
 
 4 
 
 1200.0 
 
 5 
 
 1231.5 
 
 6 
 
 1263.0 
 
 7 
 
 1294.4 
 
 8 
 
 1825.9 
 
 9 
 
 1357.4 
 
 5 
 
 1200.6 
 
 6 
 
 1232.1 
 
 7 
 
 1263.6 
 
 8 
 
 1295.1 
 
 9 
 
 1326.5 
 
 220O 
 
 1358.0 
 
 6 
 
 1201.2 
 
 T 
 
 1232.7 
 
 8 
 
 1264.2 
 
 9 
 
 1295.7 
 
 215O 
 
 1327.2 
 
 1 
 
 1358.6 
 
 7 
 
 1201.8 
 
 8 
 
 1233.3 
 
 9 
 
 1264.8 
 
 2100 
 
 1296.3 
 
 1 
 
 1327.8 
 
 2 
 
 1859.3 
 
 8 
 
 1202.5 
 
 9 
 
 1233.9 
 
 205O 
 
 1265.4 
 
 1 
 
 1296.9 
 
 2 
 
 1328.4 
 
 8 
 
 1359.9 
 
 9 
 
 1203.1 
 
 200O 
 
 1234.6 
 
 1 
 
 1266.0 
 
 2 
 
 1297.5 
 
 3 
 
 1329.0 
 
 4 
 
 1860.5 
 
 1950 
 
 1203.7 
 
 1 
 
 1235.2 
 
 2 
 
 1266.7 
 
 8 
 
 1298.1 
 
 4 
 
 1829.6 
 
 5 
 
 1861.1 
 
 1 
 
 1204.3 
 
 2 
 
 1235.8 
 
 8 
 
 1267.3 
 
 4 
 
 1298.8 
 
 5 
 
 1330.2 
 
 6 
 
 1361.7 
 
 2 
 
 1204.9 
 
 8 
 
 1236.4 
 
 4 
 
 1267.9 
 
 5 
 
 1299.4 
 
 6 
 
 1330.9 
 
 7 
 
 362.3 
 
 8 
 
 1205.6 
 
 4 
 
 1237.0 
 
 5 
 
 1268.5 
 
 6 
 
 1300.0 
 
 7 
 
 331.5 
 
 8 
 
 363.0 
 
 4 
 
 1206.2 
 
 5 
 
 1237.7 
 
 6 
 
 1269.1 
 
 7 
 
 1300.6 
 
 8 
 
 332.1 
 
 9 
 
 363.6 
 
 5 
 
 1206.8 
 
 6 
 
 1238.3 
 
 7 
 
 1269.8 
 
 8 
 
 1301.2 
 
 9 
 
 332.7 
 
 21O 
 
 364.2 
 
 6 
 
 1207.4 
 
 T 
 
 1238.9 
 
 8 
 
 1270.4 
 
 9 
 
 301.8 
 
 160 
 
 383.3 
 
 1 
 
 364.8 
 
 7 
 
 1208.0 
 
 8 
 
 1289.5 
 
 9 
 
 1271.0 
 
 211O 
 
 302.5 
 
 1 
 
 388.9 
 
 2 
 
 365.4 
 
 8 
 
 1208. 6 
 
 9 
 
 1240.1 
 
 06O 
 
 1271.6 
 
 1 
 
 303.1 
 
 2 
 
 834.6 
 
 3 
 
 366.0 
 
 9 
 
 1209.3 
 
 2O1O 
 
 1240.7 
 
 1 
 
 1272.2 
 
 2 
 
 303.7 
 
 8 
 
 335.2 
 
 4 
 
 366.7 
 
 I960 
 
 1209.9 
 
 1 
 
 1241.4 
 
 2 
 
 272.8 
 
 3 
 
 804.3 
 
 4 
 
 335.8 
 
 5 
 
 367.3 
 
 1 
 
 1210.5 
 
 2 
 
 1242.0 
 
 8 
 
 273.5 
 
 4 
 
 804.9 
 
 5 
 
 336.4 
 
 6 
 
 367.9 
 
 2 
 
 1211.1 
 
 8 
 
 1242.6 
 
 4 
 
 274.1 
 
 5 
 
 305.6 
 
 6 
 
 837.0 
 
 7 
 
 368.5 
 
 3 
 
 1211.7 
 
 4 
 
 1243.2 
 
 5 
 
 274.7 
 
 6 
 
 306.2 
 
 7 
 
 337.7 
 
 8 
 
 369.1 
 
 4 
 
 1212.3 
 
 5 
 
 1248.8 
 
 6 
 
 275.3 
 
 7 
 
 306.8 
 
 8 
 
 338.3 
 
 9 
 
 369.8 
 
 5 
 
 1213.0 
 
 6 
 
 1244.4 
 
 7 
 
 275.9 
 
 8 
 
 307.4 
 
 9 
 
 338.9 
 
 22O 
 
 370.4 
 
 6 
 
 1213.6 
 
 7 
 
 1245.1 
 
 8 
 
 276.5 
 
 9 
 
 308.0 
 
 17O 
 
 839.5 
 
 1 
 
 371.0 
 
 7 
 
 1214.2 
 
 8 
 
 1245.7 
 
 9 
 
 277.2 
 
 212O 
 
 308.6 
 
 1 
 
 840.1 
 
 2 
 
 871.6 
 
 8 
 
 1214.8 
 
 9 
 
 246.3 
 
 07O 
 
 277.8 
 
 1 
 
 309.3 
 
 2 
 
 340.7 
 
 8 
 
 372.2 
 
 9 
 
 1215.4 
 
 020 
 
 246.9 
 
 1 
 
 278.4 
 
 2 
 
 809.9 
 
 3 
 
 341.4 
 
 4 
 
 372.8 
 
 197O 
 
 1216.0 
 
 1 
 
 247.9 
 
 
 279.0 
 
 3 
 
 810.5 
 
 4 
 
 342.0 
 
 5 
 
 373.5 
 
 1 
 
 1216.7 
 
 2 
 
 1248.1 
 
 3 
 
 279.6 
 
 4 
 
 811.1 
 
 5 
 
 842.6 
 
 6 
 
 374.1 
 

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