The London (U.K) tube map is a tangle of coloured underground transport routes. The Central Line is marked in red, the Circle Line in yellow. The Piccadilly Line is dark blue, the Victoria in light blue, the Northern in black, the Bakerloo in brown, the District Line in green and so on.

Until for a short time earlier this year the winding course of the Thames River was shown as flowing south of most of all that. Not everybody, of course, wishes to travel all the way down to East Putney, Clapham Common or Surrey Docks.

Then the deed was done. While His Worship Boris Johnson, Mayor of London, was out of the country and others were not looking somebody airbrushed the Thames out of the London Transport (now Transport for London) route map. The change was meant to simplify the picture. The quick reaction showed that Londoners were not ready to dispense with what Hilaire Belloc called "the great street of the city" even though the river's ancient name, affirmed now by actual fact, translates as "dark river".

If the St Lawrence is the River of Canada, the Thames is the water highway of Commonwealth and United States history. None of those countries would be what they are had Father Thames not flowed out of England and into the sea. It is, mostly, a benign stream flowing 350 km from a field in Gloucestershire where a stone by a spring marks its source. For 2000 years a footpath that follows its course has led to London and, from there by ship, to the world.

Any Maritimer, New Englander, Ontarian or Californian - even Albertan or Texan - who does not acknowledge a debt to the River Thames should be sent back to school.

In wartime, people sang "There'll always be an England". Perhaps at Transport for London they should sing "There'll always be a Thames". Every future leader of an English-speaking state or province should travel the path from Ewen (Anglo-Saxon for 'source') to the Pool of London.

This Canadian citizen, now legally a foreigner in the land where his ancestors lived for at least a thousand years, loves the Thames as one does the Clyde, the Seine, the Danube or the Volga. It does not have the many castles, terraced vineyards and the waterfall of the Rhine, nor its storied water nymphs, but its course should be known by all who speak English as well as was the pilgrim route from Southwark to Canterbury by mediaeval people.

Before noting here some of the places one should see 'Thames side', let this be a warning not to delay your (next) visit unduly. Parts of south-east England are sinking into an underlying bed of clay. And the tides in the lower part of the river are rising. The Thames is also subject to high 'surge tides'. For many years the problem has been met by raising the level of its banks at threatened places. The Embankment, familiar to all who know London, not only holds back the water but also covers artfully important parts of the city's sewage system.

In 1953, the year of the Queen's coronation, 300 people were drowned by a flood in the Thames Estuary. After a similar tragedy in 1971 the Thames Barrier was planned and constructed.

It protects London from tidal bores and from the rising sea level as Arctic ice melts.

The Barrier, sunken into the river bed, has 100- and 200-foot openings that can be opened and closed in 15 minutes to facilitate shipping. Its height can also be raised. .

Now, returning two-thirds of the way westward up the Thames, let's start at Oxford, above which the low lying springtime fields are often flooded.

The university city is the place where the rivers Isis and Cherwell meet the Thames, the former being the site of the famous rowing regattas. At nearby Iffley the 12th Century Norman church is a 'must see' for architecture buffs. There are those who contend that the Thames really begins at Iffley Lock. Above that, they insist, the river is the Isis, into which the Cherwell flows from the north at Oxford.

Abingdon, 10 km from Oxford and 90 from London, claims to be the oldest town in England. Archaeologists trace its settlement back 3500 years. Farther down river Henley-on-Thames has its annual Royal Regatta at the end of June.

Nearby is Marlow where Izaak Walton was 'the compleat angler' and where at the Trout Inn and other hostelries one can be the complete gourmand and on any weekend meet visitors from around the world.

Farther still down stream is Windsor, overlooked by its royal castle. All lawyers and politicians should make the pilgrimage to Runnymede Meadow where King John signed Magna Carta in 1215. Jacqueline Kennedy asked that JFK's English memorial be situated there.

The Thames enters its urban captivity as it flows past historic Hampton Court in the borough of Richmond. From Richmond Hill one catches the first distant view of the metropolis just as from Richmond Hill ON one gets the first glimpses down to Toronto. As also with Scarborough, those who named Ontario towns were often remembering homeland scenes.

Then on into Chiswick where William Hogarth is buried in the churchyard and thence to Chelsea, the home of so many famous folk since Sir Thomas More. In Chelsea-Kensington one has become imbedded in London and when one is tired of London one is tired of the world. One can forget most of New York and other cities where one has lived. For all its defects, there is no part of London that one ever forgets.

In a book of aerial views of London that I gave my late wife years ago I often re-read my inscription on the front endpaper. "If in time to come I can haunt any place on Earth I shall not spend much time above the rooftops of Orangeville or Toronto. There will be only occasional revisits of Paris, Venice, Rome. But LONDON!".

Lois and I had so many happy memories of the city and of Father Thames.