Glass balance spring>>>

Nov 08, 2001,09:21 AM


In attempts to combat problems of magnetism, in the early 1800's, a few makers tried using glass in place of the steel balance spring and even in place of the balance. Most notably, the firms of Arnold & Dent and the house of Breguet experimented with glass in marine chronometers.

The springs took the form of helical springs and the balances were flat discs.

The advantages of using glass are as follows:

- Unaffected by magnetism
- Non corrosive
- Needs less compensation than steel
- Glass is cheap to make and more consistent in
mixing, as opposed to modern alloys.
- Less dense than steel and, in turn, less subject to
inertial problems.

The disadvantages of using glass are as follows:

- Glass never fully solidifies. It is known as a
a "super cooled liquid," which means, as it remains
liquid in its formed state (balance spring) it is
subject to disintegration.
- It was difficult to fix the ends of the springs to
metal parts.
- Once formed, it is nearly impossible to adjust the
balance spring.

Anthony Randall, watchmaker, has been studying the effects of glass balance springs and has made several examples. One of which is shown here.

I will not go into details of his preliminary findings, as you can refer to the Horological Journal, June & July 2000 issues for his results.

I have seen one of his testing examples and it is amazing to see this glass, a material one would never believe could be used in this way, helical balance spring, oscillating in the same manner as all others I have seen.

Unfortunately, I don't have the time to properly research and present this topic, but I thought the forum would appreciate this unique application of material and creative thought in horology.

Anthony Randall, brass balance with Dent type compensation.

Marine chronometer no. 1771, EJ Dent, glass balance and balance spring with compensation pieces.



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On a different scale, I remember reading that the make concrete springs >>>

 By: JJCASALO : November 9th, 2001-06:06
I remember reading in a magazine that some parasismic building use springs made of concrete, as on a big scale (each spring is about 2 or 3 meters in diameter - 7-10 feet), the concrete has the same elastical properties as steel, or even better. But the g... 


 By: Curtis for David Lou : November 9th, 2001-08:08

Glass- a very workable material

 By: Bill Stonehill : November 9th, 2001-09:21
Years ago I used to do glass blowing and glass springs are probably far easier to make than you might think. As a matter of fact, I think one of the (unmentioned) reasons that they were used for a short while during the middle of the 1800s was ease of man... 

Winding a glass spring

 By: BarryN : November 10th, 2001-06:18
Glass is amazing stuff! I've been around the art glass scene for the last 35+ years, a buddy is a very successful glassblower. He's doing big cast pieces now, he batches and pours 1 1/2 tons of glass 3 times a week doing lots of architectural stuff. He ha... 

Way cool! very interesting thread. does anyone happen to know

 By: ThomasM : November 10th, 2001-07:19
the resiliency and elasticity characteristics of the glass formulation we are talking about vis a vis the equivalent metallic balance spring? Does glass suffer from "fatigue" like metal does? deformation during "breathing?" Other materials qualities that ... 

Just a Wild Guess, but...

 By: Bill Stonehill : November 10th, 2001-08:20

Good Lord! I didn't know that...

 By: Tom Gillham : November 9th, 2001-06:06

An all glass clock (gears too!)

 By: Bill Stonehill : November 9th, 2001-09:21
I went back and checked if the all glass clock was still up on the internet .All the parts including gears and escapement are of glass, and the Swiss watch museum it is in is in La Chaux des Fonds. More can be read about this interesting clock at http://s... 

Thanks Bill!>>>

 By: Curtis for David Lou : November 10th, 2001-06:06

I like that clock...

 By: Saturn : November 13th, 2001-06:06