Avoid page flicker on loading

<!--
When a page loads images whose tags do not have width/height, it allocates zero space
for the image and continues filling in the rest of the document.  As an image is retreived it is
back-filled into the empty locations, causing the content of the page to jump around.  To
correct this, specify the height/width so the browser can reserve the correct space for the image
-->

< img src = "mypicture.jpg" width = 400 height = 300 >