var southWest = L.latLng(34.9816, -85.4719);
var northEast = L.latLng(35.217, -85.0462);
var center = L.latLng(35.0657, -85.241);
var bounds = L.latLngBounds(southWest, northEast);

var map = L.map('map', {
  maxZoom: 18,
  minZoom: 11,
  maxBounds: bounds,
  center: center,
  zoom: 12
});

L.tileLayer('http://chattanoogapubliclibrary.github.io/cpd-zones-tiles/tiles/{z}/{x}/{y}.png', {
    attribution: 'Map data &copy; <a href="http://openstreetmap.org">OpenStreetMap</a> contributors, <a href="http://creativecommons.org/licenses/by-sa/2.0/">CC-BY-SA</a>, Zone data &copy; City of Chattanooga, Imagery © <a href="http://mapbox.com">Mapbox</a>'}).addTo(map);

r

@@ -298,21 +298,16 @@
 eLayer('
-http:
 //chatta

Change tile URL to work with HTTP or HTTPS.