Bohman Mandolin

**danb** · Jul-25-2006, 3:31pm

Here's a really wild and rare instrument. This is a Bohman Mandolin made in Chicago back in the early 1900s. What sets this one apart from the ordinary is a set of tuning rods suspended inside the body- 4 of them to be exact.. that were tunable (or tightenable I suppose) with screws near the tailpiece, and had a clever little mute switch right next to the soundhole.

Here's the body

**danb** · Jul-25-2006, 3:31pm

Nice looking back

**danb** · Jul-25-2006, 3:32pm

I'll try several shots of this mute mechanism. It's not that distant from a ballpoint button system. You press down once, one foot of a wishbone releases a flat spring of metal with felt on it, freeing the internal rods to vibrate. They hummed very weakly when free, but perhaps some adjustment is required

**danb** · Jul-25-2006, 3:33pm

Another view of the mute, resonating rods more in focus

**danb** · Jul-25-2006, 3:33pm

Nuts to tighten the rods

**danb** · Jul-25-2006, 3:34pm

Another lousy photo, the unusual carved tailpiece

**danb** · Jul-25-2006, 3:35pm

Pretty wild tuners too

**danb** · Jul-25-2006, 3:37pm

It's playable, but I sure wonder what it would sound like with a setup on those "humming rods" inside.

Personal story- years ago at Milwaukee Irish fest I saw one of these for sale. I was pretty mystified by it. I recall the rods buzzing and ringing just like a tuning fork. The seller told me he thought they were for tuning the strings! I had no cash back then or I would have bought it out of curiousity!

**Eugene** · Jul-25-2006, 9:03pm

What a freak, from tuners to scratchplate to vibrating sympathetic rods! I suspect you know this tidbit, Dan, but Bohmann is reputed to be the earliest regular producer of mandolins in America. I never quite grasped his shop's quirky sense of aesthetic. Most of the old Bohmann bowlbacks I've come across are plagued with top cracks.

**Jim Garber** · Jul-25-2006, 9:36pm

I have seen an early 1890s Bohmann mandola. I also believe that he used those tuning rods in his violins and used sympathetic strings in some of his monster harp guitars.

Jim

**Jim Garber** · Jul-25-2006, 9:43pm

Gregg Miner has more info on Bohmann than you would ever want:

Bohmann, page 1

Bohmann, page 2

About the tone bars:

Originally Posted by

Perhaps the most famous Bohmann instruments are the “sympathetic string” instruments. Though most owners or writers have referred to these internal sympathetics as "strings," I'm positive that they are all, in fact, the metal rods specified in Bohmann’s patent # 1,128,217 of 1915. The rods were stiff, made out of specific materials (for each described note!) and tuned with wing nuts to these specific pitches just like a string. There was also a damping bar, activated via a push button in the guitar top. This invention was applied to mandolins and standard guitars, of which some examples are known. Three harp guitars of this type are known, which all appear to be from the 1914-1916 timeframe, as they include all the features included in Bohmann's next patent, # 1,179,499 of 1916. These include the sloped shoulders to provide “cutaway” access to higher frets, a bizarre hand rest, and the incredibly thick convex top and back (part of the earlier patent also).

Jim

Jul-25-2006, 9:54pm

Look for Joseph's face on the label...

**danb** · Jul-26-2006, 6:45am

Oh! It looks like Gregg has never seen one in person from that description. I'll have to fill him in

**Jim Garber** · Jul-26-2006, 9:25am

Originally Posted by (DiegoMoon @ July 25 2006, 22:54)

Look for Joseph's face on the label...

Here is another alternate label.

Jim

**Jim Garber** · Jul-26-2006, 9:28am

I was able to find that patent with some interesting description of the rods and the purpose of them. Unfortunately, they changed the formatting of the patent site and you can't actually downlaod the actual scans any more.

There was a mention in the patent tho that for the mandolins he recommends bars of 1/16 inch diam. vs. 1/8 inch for the guitars.

Jim

Jul-26-2006, 9:41am

The picture I had was from a#bowlback I sold last year. I used a small internal camera to get in and get close to his face. I love this guys labels. They are a real treat.

**Jim Garber** · Jul-26-2006, 1:42pm

Joseph Bohmann was not the humblest of luthiers...

Jul-26-2006, 2:05pm

Originally Posted by (jgarber @ July 26 2006, 14:42)

Joseph Bohmann was not the humblest of luthiers...

It's hard to be humble when you're the worlds greatest musical instrument builder

**Rick Turner** · Jul-26-2006, 3:46pm

You guys are killing me with this stuff! I love it...

**Jim Garber** · Jul-26-2006, 4:10pm

You can read the patent for the metal bars here.

Jim

**PaulD** · Jul-26-2006, 5:06pm

Dan... cool instrument. Do you have a better shot of the bridge? From the full-frontal shot it looks pretty tall. I like the fingerboard extension. It looks a little like it melted, ran onto the top, and is dripping over the soundhole.

pd