Character encoding problems (command line vs browser)

I've got a table in MySql (table, database, server, and connection all
using iso-8859-1) with some accented characters. When I try to display
these in a web browser, they come out incorrectly. But running PHP
from the command line I have no such problems. I also see the accents
correctly from the MySql client.

There is no HTML issue, because I've reverted to text/plain for the
purposes of troubleshooting. I'm not sure how this will come out for
those of you using text-only newsreaders, but this is what I'm seeing:

Command Line:
ALLÉE Allée
ÎLE Île
ÉCH Échangeur

Browser:
ALL�E All,e
×LE ×le
�CH �changeur

This is the code, nothing more than a straight database dump:
<?php
$link=new mysqli(....);
$result=$link->query ('select * from street_types');
header('Content-Type:text/plain');
while ($row=$result->fetch_row()){
echo "$row[0] $row[1]\n";
}
?>

Has anyone seen this before? Any ideas how to fix it? Thanks!