historians on either side of the atlantic. the story is told with great intelligence and sympathy. he writes books that you want to read. these are only a few of the many examples of the high praise earned by this afternoon's keynote speaker, nigel hamilton. we are grateful to have them here with us today to mark this special d-day anniversary. professor hamilton is a senior fellow in the mccormick graduate school at the university of massachusetts boston .president is the author of an impressive and a very long list of books. them are multivolume works and most of them are biographies for which he has a singular passion. wasfirst major biography published in 1978. it was followed three years

later by "monty." it was the first in a three volume work. american presidents have long been a subject of professor halton's research and writing. he authored the critically acclaimed jf k "reckless youth" which inspired a television miniseries. former president bill clinton was the focus of a two-volume caesarsy and "american ." that examined 12 u.s. presidents. professor hamilton's keen interest in biography led to the of publishers on the biography bookshop in the mid-80's. through his efforts, the british institute of biography and the first center for biography in britain was established. two of his books reflect his great enthusiasm for the study

of biography. not only has he written or cowritten, by my count, at least 25 books, but professor hamilton has won numerous awards for his writing. among them, the award for biography, the templar medal for best contribution to military history. today, reddish foreign nigel hamilton is an american citizen and his most recent work, "the was releasedmand," on may 13. it is conveniently available in our gift shop. [laughter] i know i am looking forward to reading it. these join me in welcoming our d-day 70th anniversary keynote speaker, nigel hamilton. [applause]

>> thank you very much. for that charming introduction and although i am now an american citizen, i hope you will forgive my lingering british accent. [laughter] i call my talk " d-day, 70 years ago" i begin by saying that yesterday, on the 70th anniversary of d-day, president obama traveled to normandy as our commander in chief. and the head of state. the commander-in-chief of our armed forces. which is only right and proper. the number of veterans who took part in those historic landings is diminishing by the day. we want to honor their courage as well as the supreme sacrifice of those who never came back alive.

when i was as to visit with you in the eisenhower presidential library i felt equally honored. -- deeply honored. as a naturalized american it is for me and a special privilege. for i have a special connection with d-day. my father to part in the d-day invasion, big coming in youngest british infantry battalion commander at the age of only 25. my childhood summers thereafter were spent camping in the region, normandy, where so many of my father's men lost their lives. 600 of his men became casualties in the great battle that followed the landings. out of 1000. from normandie my father went on to fight in belgium, holland.

and germany. as the allies pursued resident roosevelt goal of the unconditional surrender of the forces of not see germany. -- of notsee germany see germany -- of massey germany -- germany. nazi germany. nazi,later i got to know quite intimately phil marshall, bernard montgomery, the general who had commanded the allied land forces i d-day. and the man who took the surrender of all germany forces in holland, northwest germany, and denmark on may the fourth, 1945, less than 11 months after d-day. i was even taken by monty to spend a weekend with his hero, winston churchill, who had been prime minister. a very extraordinary privilege for a 19-year-old university student, i can tell you.

later still i was appointed official biographer of the field marshal in three volumes. i was able to interview many of hundreds of u.s. surviving and british surviving commanders in the command. -- in the normandy campaign. all serving under the supreme commander general dwight the eisenhower -- dwight d. eisenhower. , american reddish, and canadian. -- american, british, and canadian. it was unforgettable to assemble in retrospect the story of the largest amphibious invasion we will probably ever see in human history. it brought me here to abilene

many years ago in the 1980's to do research in the library's papers. and an -- in many other libraries and archives. when it was all over in 1998, i thought i should move on. i did, becoming a presidential historian for it not only writing new biographies of john f. kennedy, and bill clinton, but also a good biography of the -- a group biography of the last 12 united states president from fdr through dwight eisenhower to george w. bush. that was published in 2010. "american caesars." can everybody hear? now you can. not of what i said really matters. now it matters. it was the writing of american caesar that alerted me to the fact that no one had ever chronicled resident roosevelt's life as united states commander-in-chief.

commander-in-chief of the united -- armed forces in world war ii. from his perspective in his oval office, his map room, is maryland camp which later became camp david. his house at hyde park, and his travels across the nation and abroad. to newfoundland, to africa, cairo, tehran, the middle east, and yalta. and that seems to me, given the importance of president's role

in world war ii, wrong. so i read the privilege of revisiting the life of franklinton on of roosevelt in world war ii in two volumes -- -- franklin delano roosevelt. the firsto record for time his role as united states commander-in-chief but to set the record straight. in fact, to change history if we understand by event, the way we look at the past. and especially with regard to the d-day landings in june 1944. for the simple truth is most people have very little idea of the origins of d-day, the story of how president roosevelt

personally direct to the -- directed the military so that d-day would be a triumph and not a mass suicide and let me ask -- explain briefly. which is pretty hard for somebody raking multiple volumes. [laughter] in 1942, in the panic stricken week after pearl harbor, a time when a young major general eisenhower working in the parchment, apartment was trying -- in the war department, was trying to put together the ships to rescue his former boss, general macarthur in the philippines, the president of the united states took the reins not only of the u.s. commander-in-chief in wartime, but of the western allies.

whatever you have may read or seen of the performance of winston churchill in 1942, let me tell you that winston churchill's role was as he admitted publicly, he was only the president's ardent left-hand. it was the president of the united dates who determined the strategy of the allies. and roosevelt began this with a decision of historic importance, namely to pursue a policy of germany first, not japan first. defeating japan first would leave hitler and control of -- in control of your. -- europe. the president maintained. whereas feeding hitler first

-- whereas defeating hitler would make it thin impossible first for japan to hold out for more than a few months. and so, bucking public opinion, and media commentary, the commander-in-chief of the armed forces of the united states focused on dealing with nazi germany as america's first priority. easier said than done however. the british empire in the far east collapsed that spring, and the united states was expected to save australia on its own without british help. even british forces in egypt, defending the suez canal and access to the middle east, found themselves trounced by field marshall rommel over 30,000 british troops surrendering on

june 21, 1942, without a fight. as churchill, who was visiting president roosevelt later wrote, it was a bitter moment. defeat is one thing, disgrace is another. the difficulty for the president was not only the collapse of rigid horses across the world -- british forces across the world, but plans of the president's own generals in washington. honorable men in washington with no idea of military reality in confronting hitler in battle.

the secretary of war, henry stimson, the chief of staff of the united its army, george marshall, and the entire complement of generals and admirals in the war and navy department in washington the scold for an immediate allied -- thus called for for an immediate allied invasion of northern france, a so-called second front. either that year, 1942, or in the spring of 19 43, the most direct route to berlin and defeat of the third reich. how such senior officers in washington to and could have given their president and commander in chief such advice today is almost the on comprehension.

-- almost beyond comprehension. but they did. when president roosevelt said no, we have never fired a single shot against a single germans shoulder yet in this war, we must first gain combat and experience, they came close to mutiny. as i've tried to describe in "the mantle of command: fdr at war, 1941-1942." the secretary of war telling the president of the unit is dates -- of the united states that the president's alternative plan, to launch an amphibious invasion of northwest africa, to save the british, and to learn how to write the germans in real battle at the for this -- the furthest -- and to learn how to fight the germans in real battle at the

furthest extremity of german of communication and knock italy out of the war, they bet their own president the plan would fail. in fact, secretary stimson took a bet with the president of the united states that his invasion, that his invasion would fail. and asked general marshall was there if he was made dictator of america, he would cancel the president's great pet scheme as he called it. marshall said yes he would. he would cancel it. how president roosevelt raised faced down his generals and insist they carry out his north

african plan is dead of can -- instead of committing mass american suicide in the beaches of northern france is one of the most dramatic episodes in american history. and one with a happy ending. for torch did not fail. the president chose young general eisenhower to be it's commander-in-chief, and the torch invasion proved a brilliant success, stunning hitler and giving hope to the millions of people across occupied europe that the americans are coming. you can see the landings more in blue arrows on the north african

coast. that is at the bottom of your map. how disastrous a cross channel invasion would have been if the generals and admirals in and have had their way. it had already been demonstrated in august that year, 1942. when winston churchill often -- authorized a mini d-day targeted at a little french see part south. it is not actually marked on the map, but it is somewhat above the blue arrow southeast of dover. a brigade of canadian troops who had never been in battle be more

-- before were landed on the shore on august 19, 1942. almost 1000 were slaughtered in cold blood without ever getting off the beach, despite the tanks that had landed with them. hitler was delighted. he said to his propaganda minister that his favorite ss commander would be furious that he had not had the time to get to the battle before the enemy was wiped out. the canadiens took over 60% casualties that morning. president roosevelt has been proven right, and his generals wrong. the same thing happened then in

1943 a few months later. but with the british now giving the president grief. the president had silenced his the president had silenced his washington generals who were criticizing eisenhower for being slow to seize tunisia. large numbers of germans troops have been flown into combat. the president of cause of lincoln had made it clear he was not in the least disappointed by eisenhower's slow progress. his was exactly why u.s. forces were in the mediterranean, not in the north of france, to learn how to fight and gradually how to

efeat the germans in battle. the president was swiftly proven right. defeat at germany hands was hocking, but not shameful. north africa was an opportunity o learn the lessons of combat, of command. and if coalition cooperation of army, air, and navy, fighting ogether with our allies. in the ensuing months of 1943, in tunisia and sicily, we heard very moving stories about those invasions. the united forces did exactly hat.

learn how to defeat the forces in battle. instead of launching an nvasion when hitler had over 25 divisions waiting for us to defeat the beach. as the united states forces, including young general eisenhower himself, learned these tough lessons, the president laid down the further strategy for them to follow. in 1943, in the mediterranean, they would have the field and amphibious grades the u.s. forces needed. the spring of 1944, he got everyone to agree would be the

right moment for d-day. the moment when u.s. mass production, we have heard of rosie the riveter, when u.s. mass production of planes, tanks, and ships would make it ook just to clean -- make it logistically feasible. and a moment by which the united states would have the requisite combat and command experience, gained in the editerranean and coalition experience that would ensure he troops themselves had a ood chance exceeding -- of

succeeding in a venture that even hitler had not dared to undertake at the height of his the -- of the jury's in 940. churchill again came to washington in 1943, aboard the queen mary, with 160 staffers ensconced in the state rooms that were specially rebuilt. why did he come? he came to persuade the president if all civil to dump the d-day invasion in favor of more mediterranean ventures, or at least to postpone d-day until 1945 or 1946. 1945 or 1946? the president, who had been old in december of 1942 that already 2 million jews and other people had been exterminated by the germans in

camps, 1945 or 1946, the president in may of 1943 can be forgiven for have gotten fed up with winston. as he put it to a friend, he read churchill the riot act. he'd made it clear to churchill that he would have to be withdrawn from the mediterranean as soon as silly was in our lead hand -- in allied hands. it would be sent to britain to beat the spearhead of the invasion set forth the late 1944.

churchill did not know what had hit him. he thought that roosevelt must eat ill. have you noticed that the president is a very tired man, his mind seems closed, he seems to have lost his wonderful elasticity, churchill complained to his doctor. in truth, the president was in good health, but he was tired of the excuses that had been ade. hey had, after all saved the british in africa, and now were ready to launch a long-awaited second front that would lead to berlin. he did not want a fruitless dive version of effort in the mediterranean. he saw no reason why the united

states should agree to such a cancellation or postponement. he president stood firm. not only with serious planning made for the d-day plans, but he began to think more carefully who should command them. given churchill's obstructionism, amounting to cross channel defeatism, the president rejected the initial idea of a jewish supreme commander -- british supreme commander. if it was to be american, who

shouldn't be? it was at that point in the summer and fall of 1943 that the president began to a question the assumption which everyone had that the supreme commander should be general marshall, the chief of staff of the united states army. marshall, was the man who had opposed the president over the invasion, fearing it would fail. moreover, marshall had further disappointed the president by becoming deeply anxious lest the germans magically invade spain, cross the mediterranean, invade spain, come through spain, cross the mediterranean, and strike eisenhower's forces through the flank through spanish morocco. that is what he was so afraid of and kept in entire american army for that possibility. the president thought this absurd. in a short, for all of his administrative ability for

chief of staff, marshall did not inspire the present with the confidence that he would make a great supreme commander n the field of battle. arshall could be stiff and formal, not even the president as encouraged to address him. but above all, he could be obstinate and lacking in good udgment. good judgment, it was this ability that roosevelt sought in choosing a supreme commander

for overlord. month after month he held off the appointment for supreme ommander, leaving the invasion plan to be done by staff to the supreme commander designate. it was downright embarrassing hen they had a big summit in tehran, and they were asked to would be the overlord supreme commander. but stall all the more better then pointing the wrong man. but in the end, after meeting general eisenhower in november, here he is in cairo. this was when he was visiting and he meets general eisenhower

at casablanca. here he is again in tunis. on his way back from his summit with the marshall, the president told eisenhower, well, ike, -- our director of this museum may contest the actual wording, but we believe the president said you are going to command overlord. he had already informed churchill and the marshall and the president had informed eneral marshall, who had

accepted the president's decision with his trademark sound bite of deeply disappointed. the president met with eisenhower another three times in washington. when ike was ordered home to take a rest from his responsibilities before undertaking command of the d-day invasion forces. the president, ike found, was quite certain that d-day would be a success. and the president wanted to talk about the end of the war. unconditional surrender by the germans, and the best way to administer germany in the aftermath.

as well as the french while the ar lasted. and also be setup for a united nations organization, using the nited states is one of the world's four policemen on the behalf of the u.n. to ensure that no third reich or empire of japan or madmen ever brought the world to destruction again. it was clear to eisenhower that the president was a man who thought always ahead, and perhaps it was the key to his genius of leadership, tempered by almost incredible patience

and insurance unity of purpose. an invisible iron will that hid the president's strategy for the combat, the military conduct to world war ii, whilst following. these were qualities that eisenhower had grown to admire in the president, and worked to emulate. it was surely in the way that he personally witnessed president final moments. especially in the way the president refused to be ressured by his military advisers. or even his civilian advisers into unsound operations of war. the ending of the korean war and his refusal to go along with written, france, -- of

britain and france would demonstrate how much she and eisenhower had learned. final judgment is far more important than the fantasies of easy the three and -- victory. we do this not only to commemorate the courage of my father, your father, your grandfather, uncle's that took part in the invasion, we honor it also as a testament to the calm visionary judgment of a great president and commander in chief who directed the military in world war ii far more intelligently, diligently, commandingly, then most of us have been led to recognize. man who delayed his choice of

the supreme commander to lead he allied forces in that omentous enterprise because he anted the choice to be the right one. a choice worthy of the hundreds of thousands of american servicemen who would be risking nd giving their lives to fulfill the president's germany first policy. d-day, the invasion which, as itler knowledged, would decide the war.

as it did, leading not only to the defeat of hitler's forces in the west, but which led to the final, unconditional surrender of the german armed forces 11 months after d-day. thank you very much. [applause] i would be happy to take any questions, impersonations. i did stay with winston churchill for a whole weekend. i am told the last person to stay with the family outside of the family was myself. it was an unforgettable

xperience. i was a student at cambridge university, and my landlady called me and said, nigel, there is somebody on the telephone who says he is field arshal montgomery. i think it is one of your stupid friends. [laughter] but it wasn't, it was monty himself, who loved and admired churchill and had to go stay with him every year to cheer the old boy up. he elected to take me with him ut and it was an unforgettable xperience. he high point of which was

monty, during a pause in the conversation, -- someone asked me earlier if he was as difficult and stern as he eemed of a and he was actually a man who loved to poke fun. at one point during the dinner, as winston had speared a piece of roast venison which his wife had made, he held it up and looked at it with his whiskey glass nearby. deciding which one -- [laughter] there was this pause in the conversation, and monty said in

his ear, of course you know, winston, nigel is a socialist. wish to the conservative former prime minister -- and blessed them, he looked at the piece of venison and then looked at me, and went grrr! ake it a short question so i can repeat it. why did the british people tossed churchill out of government in 1945, shortly fter the germans signed? there is not a short answer.

the shortest i can give is that churchill was very old-fashioned. as much as i still admire sir winston, the man could command -- the mantle of command is pretty critical. he was very old-fashioned, he had served in india in 1898, ut he was absolutely determined in the 1940's, as the japanese forces were getting closer and closer to india, we even have a map. as the japanese were getting

loser, and had conquered all of the southwest pacific and had reached the borders of india, and the president pleaded with winston churchill to allow the viceroy of india to authorized the indians to form their own self-government so that the indians would fight with the british, and winston churchill absolutely refused. and when the president sent his right-hand man to try to ersuade him, winston said to harry hopkins, if they president pushes me one inch further, i shall resign. he capped 1000 troops in india to keep the people of india from getting self-government, instead of fighting.

they did nothing in the pacific. president roosevelt really had to defend and look after australia and new zealand and the south pacific on his own without british help because winston was that old-fashioned, olonial imperialist. when it came to write his memoirs, wonderful memoirs, and anyone who has not read them should. they won him the nobel prize for literature. but he sweeps all of that under the carpet.

he was descending civilized values in a wonderful way with rhetoric. is ability to invent metaphors off the top of his head, i know you know many of them. he did force the president to put the american troops in outhern italy, and when they were slow, he said they were intended to move faster not like a harvest bug. who but churchill could have come up with that? churchill had very little vision of the future. to some degree in this country he is honored politically as somebody who saw more ealistically the danger of

stalin and russian communism, i think that is very overplayed. the president was quite clear exactly what stalin was up to nd what was in his mind, and the future. ut to come back to your point, he british public wanted somebody who would talk about the future of society, of democratic society in britain.

a new deal, if you would like, for britain. they felt they had been writing, people like my dad, they felt they deserved better from the country they had served and fought for. and so the opposing party, the labour party, offered a much more visionary idea of british society with a safety net, social security and medical care. and churchill was simply blind to it. it is a complex question. the simplest answer is they did not think they could do it because the united states was

so economically powerful. they had gone through years of isolationism, and the armed forces were ranked 17th in the world at that time. lot of the equipment was very outdated. they felt if they struck uickly and efficiently, just s hitler had in poland in 1939 and the spring of 1940 in holland, belgium, france, that they could wrap it up very quickly. nd they did.

that shows the extent of japan's conquest by the spring of 1942. blitzkrieg and rampage in the pacific on a very strict timetable of get it done, don't wait, the democracies are slow, they are not ready, explains why they thought they could get away with it. they came quite close to doing it. >> returning to her comment on churchill and india. what i had was that churchill's argument was his fear of indian self-government was the fact that they would remain untouchable. >> it is not entirely garbage.

the question is, was churchill's fear of indian self-government because he hought that there would be internal strife? when the japanese were getting so close to india, they have the navy in the indian ocean and they were approaching the land borders, that the british could not afford the danger to losing india. the simple fact is winston

churchill had not been in india since 1898. i have looked through the correspondence that churchill had with the viceroy of india at the time. nd i have looked through the correspondence which churchill's ambassador had with the viceroy. some of the things that he writes to the ambassador in washington really makes you feel ashamed to have been british. churchill simply blamed gandhi. it was better not to give the indian self-government in 1942. how come singapore was surrendered to the japanese after only a few days? over 100,000 british empire troops surrendered, which included something approaching 0,000 indians who were

mercenaries. and 40,000 of those indians offered to fight with the japanese to get control of their own country. ne of the things that i so dmire, and it is a central moment in this book, is what happens in the february of 1942, winword comes in from macarthur to the white house. it is a signal from mcarthur saying that the president of the philippines, which are

still an american territory, would like to surrender or negotiate with the apanese. ou mr. president must make the decision. he intimated that he thought ossibly it was a good idea that the philippine government should surrender and therefore pare themselves the more casualties. this is during the japanese advance during the campaign.

and was another great deciding moment of the war. not just militarily but morally. and the president says no, you president kay's on, and you general macarthur are not allowed to negotiate anything with the japanese. if we negotiate with the japanese at this point the whole of the pacific is lost and we will never triumph. the fact is american troops, this is what he says in his cable, the american troops are fighting with filipinos to preserve the independence which has been guaranteed by an act of congress in 1934 to take place in 1946. we are there not as a colonial oppressor, we are there to ensure that filipinos can have freedom and independence of the united states in 1946.

we are proud of what we have done in this country. we will not negotiate with the japanese and become simply a vassal state in the pacific. to his credit, general macarthur accepted that, and explained it to the president of the philippines, and he was very upset because he could not bear the idea of the suffering that would follow, but he accepted it. that is the origins of what we said earlier, the i shall eturn. we not be able to hold it, but shall return. >> we have a polish delegation this weekend. there is no simple answer.

hurchill knew as well as president roosevelt that it would be very difficult, given the collapse of the british, ven though the british had eclared war on hitler, that it would be completely impossible for the british to defeat hitler once france fell, on their own. and that is why churchill pursued the alliance with the united states. i do not think winston hurchill ever dreamed that the united states and britain ogether could liberate poland,

iven the strength of the germans in 1942 and 1943. t simply wasn't on the cards that they could defend, could nvade and protect poland against soviet forces. there has been a great deal of discussion about it because it seems tragic to surrender to the russians knowing what they are going to do. both roosevelt and churchill knew that it was the russians who had murdered tens of thousands of polish. in order to preserve the united nations alliance with the soviet union we had to pretend that the germans were responsible for the massacre, but it was quite clear to both

president roosevelt and churchill that the russians were behind it. churchill said in 1943, speaking to a catholic cardinal, that he was very sorry, but as things look we will defeat the third reich, ut we will not be able to save oland, and it may be decades before poland will become ree. a pretty visionary statement. one more question. >> who influenced fdr? >> politically? ilitarily?

people say to me, you present a new look at fdr as ommander-in-chief. this is not we were grown up to read in our history books. e think that he left the running of the war to his senior marshals. if president roosevelt is so strategically wise and patient and farseeing, how come he never went to military college? r naval college?

ow did he know they were alking rot in 1942 and 1943? ushing for a d-day we were not ready for? at the end of the day i am not sure i can answer that. his command style was very low-key. he did not often give direct orders, he liked to allow people to make their suggestions and recommendations. some people assume that that meant he could not make his mind up. that is rubbish. general marshall told them after the war that it was weeks that he would not be able to see the president.

that is rubbish. the president maintained control of the military by not seeing them every day. churchill saw his military five times a day and was always meddling with the military and it led to disaster after disaster. not just the collapse of the british empire but even the invasion of italy. the greatness of fdr is how he rules by keeping his cards all on his own table. and none of these admirals or air force generals or army officers that are told to get on with their job, but only occasionally invited to the white house, the president of the united states is the commander-in-chief of the united states, and to this day he remains by the constitution the commander-in-chief. i think it is a wonderful

thing. i interviewed for this book the last surviving officer for roosevelt's map room. this was the forerunner of the situation room in the white house. he said, general marshall was allowed to come into the map room if the president agreed. here is the president who does not even allow his signals from churchill and stalin and intelligence, he does not allow them to come in and go out hrough the same service. they come in through one service like the army and they go out through the navy. he deliberately did not want nybody to assume that they had

the right to make strategy. only the president of the united states. and in my mind, think god he did. he saved us from mass suicide. it was difficult enough to get across the beaches, but we did. what would've happened in 1942 or 1943, we can only imagine. we can only imagine. [applause] so with your help we can change history, we can change the way we look at the past. if you spread the word, the myth that president roosevelt was standing back and letting the military run the war is a

myth. i think we have every reason to be grateful to president roosevelt, out only for the strategy he laid down on unconditional surrender, but also his choice of general eisenhower to be commander-in-chief in the mediterranean. thank you again. our you're watching american history tv, 48 hours of programming on american history every weekend on c-span3. follow us on twitter at ced is spanhistory for information on our schedule, upcoming programs, and to keep up with the latest history news. >> each week, american history tv's real america brings you archival films that help to tell the story of the 20th century. in an attempt to control the colorado river's flooding and provide water to arid regions of california and arizona, the u.s. government began construction on hoover dam in 1931, one of the largest manmade structures in the world

when it opened in 1936. the project employed over 21,000 workers and was completed two years ahead of schedule. next, a 1955 department of the interior film about the planning and building of hoover dam. the story of hoover dam explains the engineering feats necessary for construction and promotes economic and recreational benefits provided by the structure. >> in 1930, president herbert hoover, for whom the dam is named, signed the appropriation bill to begin construction. under a contract awarded in march 1931 to six companies incorporated, a combine of six major construction firms, men and machines went to work to build this dam of unprecedented size. this modern civil engineering wonder. reclamation engineers rushed to completion, specifications and design drawings.

crews completed their surveys and investigations. the thunder of man's determination to conquer the colorado reverberated between the cliffs of black canyon as construction got underway. the first major task was to divert the river around the dam site. to do this, four tunnels, two on each side, were drilled through the canyon walls. each 56 feet in diameter, they averaged 4,000 feet in length. drill holes were packed with dynamite and blasted. after each explosion, shovels and trucks entered the tunnels, muffed out the shattered rock and dumped it in nearby gulches. explosions rocked the canyon almost daily for two years before actual spacing of concrete in the dam began.