Alex just found that in 1932, A. Fage and H.C.H. Townend published an article in Proceedings of the Royal Society of London (Series A), vol. 135, No. 828, pp. 656-677, which is: "An Examination of Turbulent Flow with an Ultramicroscope".

 Are you kidding me :-)?

And were waiting until 1998 to reinvent it as microPIV?

Look at the sketch and tell me if they didn't do also Nano-PIV?

The full article is available through JSTOR: http://www.jstor.org

We are not sure if we are allowed to show here the copy of the figures which are most probably copyrighted, but it is so striking when we see such a thing and it's impossible to express it otherwise. We argue not to copy this images and purchase the original article from JSTOR.  We add the copyright notice as it is provided by JSTOR: