this is like the other example but since it has a larger dataset we start zoomed in farther, and reload the data every time the viewpoint changes instead of loading all of it when the map loads.
Modified http://cdn.leafletjs.com/leaflet-0.3.1/leaflet.js to a secure url
Modified http://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js to a secure url
https://cdn.leafletjs.com/leaflet-0.3.1/leaflet.js
https://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js