This will test your engineering skills;

http://www.bitoffun.com/video_vault/escherian-stairwell.htm 

Gday...

Sorry Vic ... this has caught soooo many - see this -

http://www.snopes.com/photos/technology/escherian.asp

Cheers - John

Don't be sorry mate, you found and answer!

Funny thing is I am a born skeptic and nearly always run these things by Snopes, slipped up on this one!

Thanks for the feedback Rocky!

Gday...

I had seen the video in an email a little while ago and was fascinated with it ... watched it over and over trying to figure out how they did it.

Finally checked Snopes and found the answer.

They were certainly very clever people who concocted and executed this

Cheers - John