We started the day by visiting the Chartres Cathedral. We entered and were entranced by the pilgrims walking the stones of the labyrinth in the nave. 
Chartres Cathedral
Then we walked around and saw the beautiful, and beautifully preserved twelfth century statues behind the choir and altar in a huge semicircle. The opportunity presented itself to ascend the bell tower, and we were in the company of a fifteen-year-old adventurer, so we hiked up some 300 steps and took pictures of the cathedral and city, pretending that the wind whistling through the high gothic tracery didn't bother us, and we were quite comfortable standing on an ancient stone platform halfway to the sky. Returning to the ground, where there was no breeze, we walked around the building, and were quite happy we did, because the side doors at the ends of the transepts are much more beautiful than the royal door at the end of the nave.
Back in the car we took the scenic route towards Paris. From Chartres we went up the Eure river to Maintenon (chateau) and then down the Gueville river to Rambouillet (chateau), east to les Vaux-de-Cernay (abbey ruins) and Dampierre (chateau and quiche for lunch), then on through Versailles, with an 
Intricately carved walls
ooh and ahh at the enormous palace which we hope to visit later, and then finally into the city, past the Eiffel Tower and the old Opera to our apartment on Rue Victor Masse, a block from Place Pigalle, where we unloaded the car to the Paris apartment we would occupy for the next 18 days.
Returning the rental car to Gare du Nord was a challenge which we overcame, involving finding the secret entrance to the underground station parking garage. We then walked back to the apartment, passing one sleeping drunk and stopping at an internet cafe (no phone in our apartment, sigh) the supermarket (french delicacies), and the boulangerie (two baguettes, one tarte) and up again to unpack and write this and add it to a growing backlog of unwritten trip 
Dan on the tower
reports.
It seems in fact that these old folks are hard pressed to do everything that a fifteen-year-old wants to do and still write up some sketchy notes -- but we try. The full reports will wait for later.
It's 72 stairs up to our apartment, which gives us some nice views -- of Sacre Coeur a few blocks north, and of the unceasing flow of traffic in the street below. The sounds are interesting, too -- music from one of the dozen or so musical instrument stores within a block of our flat, the roar of unmuffled motorcycles, the irritated honking of impatient taxicab drivers. We're fascinated at being immersed in this vibrant city! Tres bonne!
Towards the end of the day things went a little whiffly. We expected to have to turn on the electric, but we didn't know that turning on the hot 
Looking down
water required a separate switch. Before we realized we had no hot water, we did a laundry load in the washing machine in the kitchen. When we went to fetch the finished laundry, we found that the innards were jammed shut, with our laundry locked inside.
Now, our rental agent was in London. The owner lives in Italy. There was an on-site person "call only in emergency". We decided that this qualified. So we took our first neighborhood walk, up the street past the sex shops and the erotic entertainment lounges and the all-night bar, to the Metro Station at Pigalle, where we purchased a French phone card. The phone cards go into a slot in the phone in the "cabine" or phone booth. The first two phones just didn't work, and we were beginning to suspect our technique, but the third time was the charm: we left a voicemail message for the mysterious 
Cruciform copper roof
M. Souza. Then we hunted up the neighborhood Internet cafe (major businesses: phone card sales, little cubicles for making international telephone calls, bicycle rentals, and a collection of ancient computers powered by a server named Mustafa). We emailed our rental agent about the broken washer.
But before long M. Souza appeared, showed us how to start the hot water, commiserated with us on the loss of our laundry -- the Gallic shrug is also practiced by the Portuguese -- and wished us well. Our few pieces of laundry remained locked in the machine.
Being on the fourth floor (fifth to an American) we had the benefit of a good breeze most of the time. So sleeping was easy, even easier when we plugged our ears with genuine 30dB Remington sound baffles and covered our eyes with sleep masks! But first we gazed out the windows at the illuminated towers of Sacre Coeur up on the hill and the drunks singing happily below on the street. We felt like true Parisians!