Letter from Charles S. Peirce to Carlile P. Patterson
(Paris, 29.06.1880)



 
Spanish translation & annotations
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Care Messrs. John Munroe & Co
7 Rue Scribe, Paris

Paris
June 29, 1880

 

C. P. Patterson Esq.
Superintendent


Dear Sir,

I have received yours approving my suggestion to determine the absolute force of gravity here in a classical manner.

But to do this a new apparatus is necessary. It would take at last a year to get this constructed.

I cannot even get invariable pendulums made here for work this year.

It hardly seems to me worth while to go to work here with my present apparatus. I might slightly improve on my 1875 determination, but no determination of the absolute force made with any such apparatus would be up to the exigences of the

 
near future. The apparatus is a pretty good invariable pendulum, however. So that I shall carefully consider the question and either telegraph to have it sent or not.

The apparatus to determine the absolute force should be a long and short pendulum with vacuum chamber. I should be glad if we could get it made in America, say by Brown & Sharp. But Brunner would make it splendidly. It might be ordered for July 1, 1882.

Meantime, I am doing what I can about the unknown part of the flexure of Biot’s stand.

I am also progressing well with my spectrum meter reductions.

I had a long conversation with Villarceau about his device for determining the relative force of gravity by a sort of manometer. He proposes to have a glass tube with a bulb at one end and bent round onto itself and closed at the other end.

The bulb will contain Nitrogen gas and the tube will contain mercury by which the gas

 
will be compressed. In both legs of the tube there will be points as in a barometer cistern to regulate the level. The whole apparatus will turn about a horizontal axis perpendicular to the plane of the centre of the tube, and there will be a vertical circle to read the position. The tube will be tilted until the two points just touch the mercury and then the circle will be read. There are certainly some ingenious things about this. The difficulties are obvious enough. We hardly think of getting temperature nearer than 1/10 of a centigrade degree. Yet such an error would involve in gravity of .00036677 parts of itself. Or to have the gravity right to one three hundred thousandth part would involve determining the temperature to 1/1000 of a centigrade degree. Yet Villarceau says that if this is an insuperable difficulty all thermometry falls to the ground! What he proposes to do is to immerse the whole apparatus in melting ice. I don’t believe it will do. Anyway it would be as easy to swing a pendulum in a patent refrigerator. Again everybody knows that

 
the change of 0.1ºC in the fixed points of a thermometer is frequent. This is produced by a change of 1/50.000 part in the volume of the bulb. Such a change would affect gravity in the same ratio. Villarceau proposes to obviate this by using a number of different tubes. On the whole I don’t think we can hope for much from this instrument.

Villarceau is also studying to adapt his regulateur to the determination of gravity. I don't believe he will succeed.

He has written a long paper on the effect of the knife-edges on pendulums which seems to me rubbish. He proposes cylinders of 5mm diameter; precisely what I have tried and found a failure.

Your instructions do not authorize me to take a seat in the geodetical association as a regular delegate. What am I to say in reference to the entrance of our Survey into the association?

 

Yours respectfully,

C. S. Peirce
Assist.

 

Transcription by Sara Barrena (2018)
Una de las ventajas de los textos en formato electrónico respecto de los textos impresos es que pueden corregirse con gran facilidad mediante la colaboración activa de los lectores que adviertan erratas, errores o simplemente mejores transcripción. En este sentido agradeceríamos que se enviaran todas las sugerencias y correcciones a sbarrena@unav.es
Proyecto de investigación "The Cosmopolitan Peirce: Cartas de C. S. Peirce en su cuarto viaje europeo (abril-agosto 1880)"

Fecha del documento: 17 de septiembre 2018
Última actualización: 17 de septiembre 2018
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