<div id="container" class="js-masonry" data-masonry-options='{ "columnWidth": 200, "itemSelector": ".masonryImage" }'>
    <div class="masonryImage">
        <img src="http://topknot.ca/wp/wp-content/uploads/2013/10/kitten.jpg" alt="">
    </div>.....

var container = document.querySelector('#container');
var msnry = new Masonry( container, {
  columnWidth: 200,
  itemSelector: '.masonryImage'
});
// layout Masonry again after all images have loaded
imagesLoaded( container, function() {
  msnry.layout();
});