sloooooow apache

[rnewton3@csc.com]

Any Apache geniuses have an idea about this; I want to create a strictly
limited access web server, available only to selected IP addresses.
>From the Apache documentation I understood that you could allow specific IP
addresses using the 'allow from' line. So I changed the access.conf file
from

order allow,deny
allow from all

to

deny from all
allow from 141.245.104.215
allow from 141.245.104.225
...
28 more IP addresses.

For a total of 30 allow from lines.

Now the problem is that in the former case Apache flies but everyone who
knows the URL
can view the server and in the latter case, if you're not on the list you
don't get in but Apache
is a dog to run. It can take upwards of two minutes to load the index page!
Now even with my naive understanding of Apache this seems a tad slow.
Recommendations please, what am I doing wrong to make it run SO slow?
What is the best way to limit access to 30 non-consecutive IP addresses?
Any suggestions at all?

Thanks.