Questions re Mt. Diablo Letter Message Board: Letters: Questions re Mt. Diablo Letter

By Curt Rowlett (Curt) ( - on Tuesday, November 21, 2000 - 06:30 pm:

I know that the source is a somewhat dubious one, but I am researching for a new Z article and came across this in Gareth Penn's Times 17 on page 120. He is writing a chapter about the Mt. Diablo letter and states, "It was this letter in which the Zodiac suggested the radian exercise. On the second page of the letter, which is still unpublished as of now, he said that the police would find 'something interesting' if they placed a radian on Mount Diablo."

Does anyone know if it is in fact true that:

1. The second page has still not been published?

2. If Zodiac really wrote on that "unpublished" second page that "something interesting" would be found by placing a radian on Mt. Diablo?

I have never heard this from any other source. Can anyone verify if the two facts outlined above are true? And if they are not, what is the real story?

I apologize if this has already been discussed elsewhere on here, but I did search through the messages and the photos of all the Z letters on this site (and on Jake Wark's site) for anything related to my questions and haven't found it.

P.S. Again, I know enough about Penn and the controversy surrounding him, i.e., that his theories have to be taken with several large spoons of salt, so please don't use this simply as an opportunity to start slinging arrows. (I agree that Penn is bogus in 95.3% of his Zodiac theories, so you would only be preaching to the choir).



By Tom Voigt (Tomvoigt) ( - on Tuesday, November 21, 2000 - 07:38 pm:

The entire letter is published on my Rare Zodiac Letters page, called the Mikado letter. Page 2 doesn't feature what Penn claimed.
What a shock.

By Jake Wark (Jake) ( - on Wednesday, November 22, 2000 - 04:30 pm:

Curt, Penn claims that the passage quoted above was distilled through his father's memory -- Penn pere was a statistician with the CA Atty General's Office, and had looked at several letters but apparently never made copies. My guess is that Penn fils got the Mikado letter and the Mt. Diablo letter mixed up, since the Mikado letter mentioned the radians and the Mt. Diablo map wasn't published until the 1990s.

"This is the Zodiac Speaking..."

By Curt Rowlett (Curt) ( on Wednesday, November 22, 2000 - 05:36 pm:

Jake: Thanks. Further reading in Times 17 since making the above post reveals that Penn made the same mistake twice that you point out above.

He also wrote something about Zodiac having specifically directed that a bomb could be found (and I'm paraphrasing here) by measuring "4 inches along the radian."

I have read through all of the Zodiac letters, cards, etc. and haven't found a single place where that specific "4 inch" measurement is mentioned by Zodiac, so I'm wondering where Penn came up with that one! (And I'm not trying to get anything started here, but I swear, everytime I get into Penn's book, I am always reminded of Don Quixote jousting with a windmill).

Anyway, back to reading. If I solve the bomb cipher, plot all the radians, and find the bomb, I'll let y'all know.


By Curt Rowlett (Curt) ( on Wednesday, November 22, 2000 - 05:47 pm:

Jake: Almost forgot, but I wanted to let you know that the link to your story "It's About Time" on your website is broken.


By Gregorypraxas (Gregorypraxas) ( - on Wednesday, November 22, 2000 - 07:12 pm:

"...everytime I get into Penn's book, I am always reminded of Don Quixote jousting with a windmill)."

Hey, hey! Let's not insult Don Quixote in this comparison :) After all, despite the perpetuated myths about him, Don Quixote was well aware that the windmills were not giants. Now, Penn, on the other hand...

DQ is my favorite book, and I collect old editions. I've been lucky enough to get an 1865 edition illustrated by Gustave Dore, and a 60s edition illustrated by Salvador Dali, to name a few. The book, and Cervantes, have had a great impact on my life, and many others.

Just didn't want to see ol' DQ compared to Penn. After all Don Quixote knew when to give up! :)

By Jake Wark (Jake) ( - on Wednesday, November 22, 2000 - 07:38 pm:

Curt wrote:
"I have read through all of the Zodiac letters, cards, etc. and haven't found a single place where that specific "4 inch" measurement is mentioned by Zodiac, so I'm wondering where Penn came up with that one!"

Here's my guess. If you look at the Mikado letter's footnote, you'll see that the ampersand kind of loops around itself. Immediately following this is the number sign (pound sign for you voice-mailers) superscripted, apparently as an afterthought. I suggest that Penn Sr. mistook the ampersand for a numeral 4, and the number sign for quote/inch marks, thus arriving at an apocryphal and redundant 4" inches along the radians instead of + # inches along the radians . He then passed the misinformation onto Penn Jr, who in turn misrepresented it as a direct quote rather than secondhand information.

"Jake: Almost forgot, but I wanted to let you know that the link to your story "It's About Time" on your website is broken."

Yeah, I had to overhaul that section in light of some bad information of my own. It will probably reappear in some form, but for now I'm going to have to scrap the link rather than fix it. Thanks for the tip, though.

"This is the Zodiac Speaking..."

By Jake Wark (Jake) ( - on Wednesday, November 22, 2000 - 07:41 pm:

Hey Gregorypraxas, speaking of Spanish literature, you think "cid" as in "More glory in killing a cop than a cid" has anything to do with "El Cid?"

Nah, me neither...

"This is the Zodiac Speaking..."

By Ed N. (Edn) ( - on Thursday, November 23, 2000 - 01:51 am:

Hadn't thought about that one... sort of like how "cerous" has to do with "of, relating to, or containing cerium?"

By Curt Rowlett (Curt) ( - on Thursday, November 23, 2000 - 09:11 am:

Jake: I gave the Zodiac letter with the "P.S./Radians" notation a close examination and I believe that your explanation above re Penn's "4 inch" measurement mistake is the most logical answer.

Thanks. (You are a darn good detective).


By Jimm (Jimm) ( - on Saturday, December 23, 2000 - 07:54 am:

Looking at the Phillips 66 map and the "clew" Z
gave saying it concerned Radians and inches I observed the following- the zodiac symbol on Mt.
Diablo has an arrow head at the top pointing to the zero. Does this mean 0 inches? The "clew" copy
I was looking at was kind of blotched- it looked
like there was an arrow head under the "#", maybe
meaning he was indicating the number of inches was
zero. On the other hand it all maybe means nothing
and was sent to get the investigators spinning their wheels going nowhere, and it did get a lot of police officers going for school bus rides putting up with the endless wit juveniles are capable of.More humility for the "meanies".

By Jud Johnston (Jud) ( on Wednesday, March 21, 2001 - 07:32 pm:

I believe something is possibly being overlooked with this whole radian discussion. Zodiac mentioned "inches along a radian". This is geometrically and physically impossible. A radian is an angular unit; one can neither measure nor travel in linear units "along a radian". One can proceed "through" a radian in angular units such as degrees, minutes, seconds.

My point is this: I don't think Zodiac knew what a radian is. I think he intended to convey the notion of a straight line emanating from a fixed point, which is the definition of a radiant. The fixed point in this case, of course, is Mt. Diablo.

Having said that, I don't think it really changes much in a practical sense. Even thinking "radian", one still winds up drawing straight lines from Mt. Diablo; but I think we can dispense with the idea of 57+ degrees meaning anything.

I doubt that he buried a bomb on the line, also.

By Jake (Jake) ( - on Wednesday, March 21, 2001 - 08:06 pm:

Jud, you don't think he simply meant "along the leg of the radian?" Or maybe along the arc? With BRS-Diablo-SF so close to 57-58 degrees, the coincidence is just too great for me.

"This is the Zodiac Speaking..."

By Ed N (Ed_N) ( - on Thursday, March 22, 2001 - 12:25 am:

Jud: quite the contrary, while I think that Z was no mathematical genius, he was no moron either. He almost certainly had some college education, and knew precisely what a radian was. Think about the length of the code: only 32 characters, with 29 different symbols. As I've pointed out in other posts on this subject, it takes far less characters to write out an angular measurement in radians than it does in degrees. And, of course, the shorter the code, the more difficult it is to decipher.

What I think he meant, and it's the only thing that makes sense, is that the code would yield an angular measurement in radians and a linear measurement in inches, which one would measure clockwise from 0 on the map (as evidenced by the clockwise sequence of 0, 3, 6 and 9), and from the center of the "magnetic indicator," one would measure along the terminal leg of the angular measurement the number of inches Z specified in the code.

I think you're correct on the last point though. I don't think Z buried anything either.

By Howard Davis (Howard) ( - on Thursday, March 22, 2001 - 02:18 am:

Jud- FYI, my suspect worked as a road surveyor for the Dept. of Commerce Public Roads in AZ and was studying for some time to prepare for the surveyors test.I have read road surveyor texts and the magnetic north/compass/radians, etc.Zodiac depicted on the map and card, delineated and expounded on throughout these books.My guy took Geometry ,Algebra and Chemistry,etc. in school and he had about two years of college.Zodiac had about enough knowledge, as we say, to make him dangerous-literally!

By Peter_H (Peter_H) ( on Thursday, March 22, 2001 - 09:01 am:

Z may not have buried anything, but I believe he chose a site and at least began preparing it. Hence the comment that he was swamped out by recent rains. I have offered a theory on just where he did this, (see "the Unit Circle" under "Theories", this MB) which is consistent with all of his bomb diagrams _and_ with being swampd out by rain: It faces the September rising sun, is located on an elevation next to the road as well as a streambed that would flood in heavy weather. At one point Sandy was going to check it out, but we never heard back from her. Anyone else in the area want to take a look? (see Unit Circle" thread for the location)

By Classic (Classic) ( - on Thursday, March 22, 2001 - 11:33 am:

Z went through a lot of trouble pointing everyone to a specific spot on the map. I doubt that he planted a bomb there,but I suspect he might have put something else there. As to what it might be I have no idea. Another cipher,part of stines shirt, who knows?

By Lapumo (Lapumo) ( - on Friday, December 21, 2001 - 06:36 am:

Earlier in this thread,Ed wrote "sort of like how
cerous has to do with of,relating to,or containing
cerium"?...Interestingly Cerium is most commonly found in the ore orthite(European term)or as it's called in the US,Allanite!!!!!.I wonder?

By Howard Davis (Howard) ( - on Saturday, December 29, 2001 - 06:12 pm:

Also,another word related to that mineral is Ceres.Of course, she was a goddess in mythology and her father was Saturn.Rites for the dead were connected to Ceres.Her Festival was on April 19th ,the same day when Z wrote a letter in 1970(of course,it was postmarked the 20th).Legal matters were tied in also.Direct Hit and other search engines have some interesting material on Ceres.The city Ceres ,in Central California,is actually in the center of CA.!It is also fairly close to where Z abducted KJ.Just musing.

By Roger Redding (Roger_Redding) ( - on Saturday, December 29, 2001 - 08:28 pm:

Of course we all know who the congressman from Ceres, CA is.


By Howard Davis (Howard) ( - on Sunday, December 30, 2001 - 12:53 am:

A Cereial killer?