It's recommandated to calibrate your monitor for best viewing of these images.
A none fully black square on the left or fully white square on the right suggest that contrast and light must be ajusted.
Other tone than black, gray or white visibled in the gradient manifest that a color calibration is more than recommended. You can use for instance the Adobe Gamma software. If it's not installed on your computer
Download Adobe SVG Viewer
and follow instruction to choose the language and version of your system.

F11 With the Windows Explorer do not forget to use keyboard F11 to display full screen and visualize the website in the best condition.

In each page of slide show:
— The <<prev<< and >>next>> button let you run the slide show manualy; you can also jump to the next picture with a simple click of mouse on the picture displayed.
—The On / Off button indeed starts and stops the automatic slide show by changing pictures every 10".
With a connection by classic modem 56 Kb when the traffic is heavy on internet, it is possible that the timing of the slide show becomes too short to download the entire picture at the first try. If you don't see the full picture, turn off the slide show for a while and run manualy the change of pictures.
Than you can run the slide show automatically
— In the row of numbers | 1 | 2 | 3 | 4 | 5 | 6 |...the number of the picture displayed stays gray and the others colored numbers allow you to access the pictures of your choice.