Slow portfolio page

Hello,

Please look at this page:

http://www.desaunois.nl/vrijstaande-woningen/arkelwoude/

On some systems the page loads really slow or stops loading a bunch of pictures.
So you can see for example the first 30 pictures but the rest is blank or blur.
It looks like a speed thing, but this page:

http://www.desaunois.nl/showroom/

also needs to load about 50 pictures, and this page always works fine!

So we think it’s something with the portfolio-page and the technique of that page.

Can you please tell me how to change the loadtime?

Greets Jeen