The Pyramids of Yaruqui

The Pyramid at Caraburo today
https://media.sciencephoto.com/image/t8350543/800wm

Rising incongruously from the flat plain, the so-called "Pyramids of Yaruqui" - at Caraburo and Oyambaro -  stand as a curious memorial to the French geodesic expedition in Ecuador. In theory their purpose was to mark the two ends of the baseline for future surveys -  perhaps a triangulation to the North or perpendicular to the Meridian. In reality, they were  intended chiefly as a monument to French scientific pretensions:

French scientists at the Equator, 1735

Voyages of Discovery:  the Figure of the Earth (BBC,2006)
https://www.bbc.co.uk/programmes/b0074t5l

Last week BBC4 repeated a documentary on the French geodesic mission of 1735, one of the Voyages of Discovery series introduced by explorer and broadcaster Paul Rose.  It was originally broadcast in 2006.   Having missed it the first time round, I was pleased to catch the repeat.  The production was  marred by some truly dreadful dramatic reconstructions which made La Condamine and his colleagues look like caricatures out of Horrible Histories.  However, the filming on location in Peru was stunning. The historical consultant for the programme was the American naval historian Larrie Ferreiro, who has since written a well-regarded full-scale study of the expedition.(Measure of the Earth, published 2011)

I found it difficult in places to piece together events from the information given, so here is a summary of the main points of the narrative, plus a few supplementary "viewing notes".

Shock and Awe: the Marly experiment

BBC Four is currently repeating Jim Al-Khalili's documentary,  "Shock and Awe: the Story of Electricity",  which was first broadcast in 2011.  The first episode is devoted to 18th-century discoveries.   Catch it if you can, before it disappears from i-player as it is a brilliant programme - the camera work is stunning throughout.  There is no gimmicky docudrama, just Jim recreating the original experiments in a load of unusual locations: Charterhouse and the Royal Society in London, Leiden and the University of Bologna.

One of the most satisfying of the early experiments in electricity took place in France at Marly-la-Ville.  How could it be proved that lightning, most awe-inspiring of God's wonders, was really an electrical phenomenon?  Easy.... Stick a long metal rod in a wine bottle and wait for the storm.....!   Here is Jim on the very spot (on location in someone's back garden):  

Franklin had first outlined his experiment in 1751, in a letter to the Royal Society in which he had also advocated the use of lightning rods.  The Royal Society had refused to include his speculations in its transactions, so Franklin printed the letter himself in a book entitled Experiments and Observations on Electricity (Philadelphia 1751)

Buffon was not particularly interested in electricity, but when Franklin's little book fell into his hands, he saw an opportunity to score against his enemy Réaumur whose protegé the abbé Nollet, had opposed Franklin's theories.  Buffon's schoolfriend and collaborator, the botanist Thomas-François Dalibard translated the book into French with an insolent Avertissement attacking "hack physicists". The two hired a public demonstrator in "experimental philosophy" called Delors to repeat Franklin's earlier experiments.

On 3rd February 1752 Louis XV himself was invited to a demonstration, hosted by the duc d'Ayen at St Germain-en-Laye. The monarch was so appreciative that it "excited in Messieurs de Buffon, d'Alibard and De Lor, a desire of verifying the conjectures of Mr. Franklin, upon the analogy of thunder and electricity".

Plate from Expériences et observations sur l'électricité 2nd, ed. 1756, vol.2

Dalibard had previously installed a small laboratory in the grounds of the house in Marly where he lodged and it was here that he set up his insulated pole in early  May 1752. On 10th May it thundered in Marly. The former dragoon charged with the experiment, whose name was Coiffier, ran to the pole and presented to it a brass wire stuck into a glass handle; he was the first man ever to see a spark drawn intentionally from the sky.  Coiffier alerted the curé, Raulet, who repeated the experiment "at least six times in a period of four minutes, each trial lasting as long as "a pater and an ave".

On 13th May Dalibard reported the Marly test to the Academy of Science. 

Dalibard's house and garden in Marly-la-Ville

There was now no doubt that lightning was indeed electricity.  News of the triumph spread rapidly. The furious Nollet, who had not heard of Franklin, thought at first that the great man was Buffon's malicious invention.

In June 1752 Franklin himself famously (though possibly apocryphally) confirmed the findings by flying a kite in a storm, with a key attached to it by a silk ribbon. Once the ribbon became wet, he was able to generate a spark and charge a Leyden jar from the key.  Although Franklin now diverted his attention to politics, his lightening rods were soon set up in Philadelphia and Boston.  Nollet was forced to give up his attacks on Franklin, who was accepted by the Academy of Sciences and became the darling of French society.




Letter of Father Raulet to Dalibard 

 I can now report, Monsieur, the news that you have been waiting to hear: the experiment has been carried out. Today at twenty past two in the afternoon, thunder was heard directly over Marly; it sounded quite strong. My desire to serve you, and  my own curiosity, took me away from my armchair where I had been reading;  I hurried to Coiffier's house, meeting on the way a child whom he had already dispatched to fetch me.  I redoubled my pace in a torrent of hail. 

I arrived at the place where the bent rod had been placed, and advanced slowly towards it with the brass wire.  When I was an inch and a half away, the rod emitted a small blue column of fire which smelled of sulphur; it hit the end of the wire with some force, making a sound as if the rod had been struck with a key.  I repeated the experiment at least six times in a period of four minutes, in the presence of several people, and each test lasted the the time it took to recite a pater and an ave. I tried to continue but the effect diminished gradually; I approached closer, but produced only a few sparks, and finally nothing at all.

The thunder which had started events was not repeated;  a heavy storm of hail brought an end to the proceedings.

In the course of the experiment I received a shock on my arm just below the elbow;  I was too preoccupied with what I was doing to be able to say whether it came from the rod or the wire. I did not complain at the time, but since the discomfort continued, on my return I uncovered my arm in the presence of Coiffier. We observed bruising right around it as though my naked arm had been struck by a blow from a brass wire.  Leaving Mr Coiffier, I met the Vicaire, M. de Milly and the Schoolmaster, to whom I reported what had happened.  All three were  certain that they smelt an odour of sulphur which grew stronger as they approached me. I still had the smell about me when I arrived home;  my servants pointed it out without me mentioning it to them.

Such, Monsieur, is my account. It is written in haste, but I vouch for its veracity and will testify to the events whenever I am called upon to do so.  Coiffier was the first to perform the experiment and he repeated it several times;  it was only afterwards that he sent for me to come.  If other witnesses are needed besides him and me,  I am sure  you will find them.  Coiffier is anxious to leave. 
 I am yours, respectfully, Monsieur,

Raulet, Priest of Marly.  10th May 1752.

References

BBC Four: Shock and Awe - programme website
http://www.bbc.co.uk/programmes/p00kjq6d

Papers of Benjamin Franklin, Founders Online (U.S. National Archives): 
“Thomas-François Dalibard: report of an experiment with lightning, 13 May 1752,”   
http://founders.archives.gov/documents/Franklin/01-04-02-0105
Jean-Antoine Nollet: Letters on Electricity
https://founders.archives.gov/documents/Franklin/01-04-02-0154
Various documents collected and translated by Robert A. Morse as part of a course at Tufts University:
http://www.thephysicsfront.org/document/ServeFile.cfm?ID=3434&DocID=2513&Attachment=1

See also:
 J. L. Heilbron, Electricity in the 17th and 18th century (1979), p.348-50.
https://books.google.co.uk/books?id=UlTLRUn1sy8C&pg=PA348#v=onepage&q&f=false

Some early thermometers

Record-breaking Fahrenheit thermometer 1718

Not French I know, but it isn't very often that antique thermometers make the national newspapers. In 2012, this thermometer, one of only three known examples manufactured by Fahrenheit,  was sold by Christie's in London for "a whopping £67,000"!

References
"Thermometer from 300 years ago made by Mr Fahrenheit sells for a whopping £67,000 at auction". Daily Mail  article of 10.12.2012
http://www.dailymail.co.uk/news/article-2215558/Thermometer-300-years-ago-Mr-Fahrenheit-sells-whopping-67-000-auction.html
"Third original Fahrenheit thermometer surfaces", The History Blog, post dated 11.09.2012  http://www.thehistoryblog.com/archives/19606

The first thermometers in France

The first viable thermometer is generally considered to have been the "Florentine termometer" invented under the patronage of Ferdinand of Tuscany in 1653. This was an alcohol thermometer, with sealed tube and bowl, usually calibrated using 50 divisions.  The Florentine Accademia del Cimento distributed a number of such instruments around Europe and created a short-lived network of observers. In May 1658 the very first thermometer to reach France was sent to the astronomer Ismaël Boulliau from Warsaw by his correspondent Pierre Desnoyers who was secretary to the Queen of Poland.  Boulliau's manuscript observations for 1658-60,  conserved in the collection of the Paris Observatory, have been utilised by Daniel Rousseau in a paper of 2013 to reconstruct average temperatures for the period 1658-75.


 Thermometers used by La Hire and Morin

La Hire began his observations in  1669, again using a "Florentine" thermometer, this time constructed by the Parisian glass-blower Hubin.  Delisle in 1749 made comparative measurements with this very instrument and described it in detail:  filled with coloured esprit de vin,  hermetically sealed, it had a bowl of  5 centimetres in diameter and a substantial tube of 1.3 metres in length.  La Hire sited it in the unfinished east tower of the Royal Observatory which was open to the air but shaded from the sun.  It remained in the Observatory for almost a century  - comparative reading were taken at various times, notably in 1732 and 1754 using Réaumur thermometers.  In  1776 it was no longer to be found and assumed to be broken.  A second thermometer belonging to La Hire which was in the possession of the instrument maker Mossy in the 1780s may be tentatively identified with one on display in 1992 in an office of the Academy of Sciences (see Legrand & Le Goff, p.265).  The thermometers of Morin are known only by inference.  It can be deduced from his series of measurements that he used three different instruments in the course of his observations, adapting the scales so that zero was the mid-point.

Reconstructions of the series of Louis Morin:

Legrand J.-P. et M. Le Goff, 1992 : Les observations météorologiques de Louis Morin. Monographie n° 6, Direction de la météorologie nationale, tome 1, 36 p, tome 2, 176 p.
http://www.ipgp.fr/~legoff/Download-PDF/Soleil-Climat/Legrand_LeGoff_MeteoXVIIe.pdf
Daniel Rousseau, "Les moyennes mensuellesde températures à Paris de 1658 à 1675"  La Météorologie - n° 81  mai 2013

http://documents.irevues.inist.fr/bitstream/handle/2042/51098/meteo_2013_81_11.pdf

 Early Réaumur  thermometers

Although interest in meteorological observation was more marked by the early 18th century, thermometers were still few and far between.  Few of Kanold's observers had a thermometer and there were none at all in the American colonies prior to 1715. According to the abbé Nollet, measurements were "vague and uncertain" since  instruments had no fixed starting point and varying scales.  Scientists sought ways of improving the situation. In 1717 Daniel Fahrenheit built his famous mercury thermometer with 32° for freezing point of water and 96° for temperature of human blood. In France René-Antoine Ferchault de Réaumur  reverted to an alcohol thermometer but proposed 0° for the freezing point of water and 80° for its boiling point.  Like the Florentine thermometers, Réaumur's first instruments  were enormous (1.6 m in length).  The abbé Nollet, who directed  Réaumur's laboratory from 1733,  subsequently improved the design by refining the calibrations and reducing the length of the tube.  According to Louis Cotte, writing in 1765, the Réaumur's instrument  represented the first crucial step towards standardisation:  "one can build such thermometers, that function comparably, anywhere and any time". 

Louis Cotte;  Réaumur  thermometers, at the centre: "the great thermometer as Réaumur first built it"

 Louis Cotte, Traité de météorologie (1774); Livre second: "Des Instruments météorologiques"
http://gallica.bnf.fr/ark:/12148/bpt6k94863w/f135.image
Plates from the treatise of père Cotte:

http://libraries.ucsd.edu/speccoll/weather/b4164163.html

Duhamel's château de Denainvilliers claims to have the oldest surviving thermometer in France. The château, which is now open to the public, preserves Duhamel's workshop and, in the adjacent bathroom, where he conducted his meteological readings, his barometer and Réaumur thermometer. Sadly, there is no photograph to be had.
http://www.loiret.fr/chateau-de-denainvilliers-patrimoine--21281.htm?RH=R8.3.5


In the winter of 1776 Louis XVI inquired whether it  was as cold as it had been in the great frost of 1709.  The lowest temperature of 1709 had been marked on La Hire's thermometer but this was no longer extant.  However his scale had been compared in 1732 with a thermometer of Réaumur which still existed.  There was much dispute over the figures, but  finally Lavoisier concluded that the winter of 1709 was colder "by 20 degrees than the winter of 1776"

In this early Réaumur thermometer the scale is drawn in ink on a paper sheet, glued to the wooden tablet.  The extreme cold of 1709  (−15.5 °R ) and of 1767  ( −12.5 °R) have been marked. See:
https://www.researchgate.net/figure/226562950_fig3_Fig-3-Evolution-of-the-technology-in-building-thermometers-in-the-18th-century-and-at 

The weather - some 18th-century French observers

The prodigious quantity of  causes ... troubles us, makes us afraid, and hides from us the secret of the Creator.  It is beneath appearances that are deceptive only to us that is hidden the wisdom of His admirable operations...So much has research into effects been neglected in favour of causes, that all we have done in physics is babble.  If Nature is better known today than in the centuries of ignorance, it is because we apply ourselves  more to the knowledge of effects than causes, and we use the accumulated knowledge of these different effects to find true causes.
Louis Le Cotte, Traité de météorologie


Early observers:  La Hire, Maraldi and Morin

The first significant series of air temperature readings in France was begun at the newly constructed Royal Observatory in 1669 by Philippe Le Hire (1640-1718) and continued after 1720 by Jacques Philippe Maraldi (1665 - 1729).  A geometer and surveyor, Le Hire's interest in meteorology was prompted by his surveying work in the 1680s for the water supply at Versailles. As he explained in a memoir of 1704 the practical requirement of Louis XIV's cisterns prompted him to make exact observations of rainfall; he noted that it rained more when the air was lighter as measured the descent of the mercury in the tube of the barometer and resolved to compare rainfall with both air pressure and temperature.  Le Hire's complete registers of temperature readings do not survive, only his summary reports to the Academy of Sciences which were concerned mainly with annual extremes and unusual weather events.

The first complete series of observations for France were  made by the Parisian botanist and doctor Louis Morin (1635-1715). Morin was a physician of some repute, numbering Boileau, Racine and the Princesse de Joinville among his patients. After the death of the Princess in March 1688, he retired to the Abbey of Saint-Victor near the present site of the Jardin des Plantes.  In  1692 he was made a "Botanical associate" of the Academy of Science and 1707 became a full member,  succeeding  Louis XIV's doctor Denis Donard. Fontenelle's official Eloge, noted that his life observed "an order almost as uniform and precise as the movements of the celestial bodies". Since Morin was a  botanist and physician rather than a physicist, he presumably hoped to elucidate the influence of climate in these areas, though his work seems never to have progressed beyond the collection of data.

Morin's metereological registers span a phenomenal forty-eight year period, from February 1665 to July 1714.   He took readings three or four times a day, including measurements of temperature, barometric pressure and humidity (hydrometry), plus observations on clouds, direction and force of the wind, rainfall, snow and fogs. The most complete series are the thermometer and barometric readings [Manuscrit. Ms 1488, Bibliothèque de l’Institut de France, Paris]  In 1992  the metereorologists Jean-Pierre Legrand and Maxime Le Goff  were able to use this register to reconstruct daily temperatures for the period 1676-1713.

After 1715 there was a general upsurge of  interest in the collection of meteorological data among the learned societies of Europe, coupled with a recognition of the need for networks of observers.Johan Kanold in Breslau compiled readings from a dozen locations across Europe, and in 1723 James Jurin, the secretary of the Royal Society, laid out a plan for daily recording of barometer and thermometer readings, wind strength and direction, precipitation and state of the sky.  The English network eventually boasted fifteen observers, ranging from Bengal and St. Petersburg to Massachusetts.  The weather diaries were collated by the indefatigable William Derham who was a Fellow of the Society.  
By the 1740s these early initiatives had largely floundered. Derham submitted his last series in 1734 and it was finally published in 1742.  In France Le Hire and his successors felt that they had failed to receive the recognition that they deserved; In 1743 Du Hamel was to complain that science based on observation had been sacrificed to the superficial éclat of  the system builders. In part results fell short of expectations due to lack of equipment.  But the real problem was lack of  any practical application  - there was little to do with the data  other than compiling reports and reading them. Jurin had hoped to be able to predict weather from patterns in the data but,  although observers  sometimes drew parallels between conditions in different locations, they failed to understand that they were part of a single weather system (See Feldman, p.151)


Duhamel and meterology in the mid-century

With the mid-century France came a new awareness of the importance of the study of climate for public health and agriculture.  The term"climat" in this period encompassed a whole range of environmental conditions, not all of them strictly atmospheric. ( See Montesquieu's famous speculations on the relation between "climate" and national character in L'Esprit des Lois, which was published in 1748)  In medical theory "humours"were  replaced by the idea  that environmental factors - hot cold, wet, dry -  acted mechanically on the body.  Exponents hoped to correlate weather patterns with disease; as for example,  Paul Malouin in his History of epidemic diseases, observed at Paris, with differences of  air temperature, which was published annually from 1746 to 1754.  Agriculturalists boasted less theory, but there was a general perception that the success of crops could be studied in relation to the weather.

The chief observer at this time was Henri-Louis Duhamel du Monceau (1700-82). who  from 1741 to 1780 addressed to the Academy of Science a series of annual Botanico-Meteorological Observations in which he presented tables of meteorological data and general remarks on crops and public health. His efforts provided an important model for later initiatives.
.

Duhamel's published summary of observations for March 1753

The Château de Denainvilliers in Gâtinais, where Duhamel carried out much of his work

Louis Cotte and later meteorology 

In the second half of the century, particularly in the decades 1770 to 1790, the study of medical and agricultural climatology expanded in line with growing government intervention in public health.
 The number of observations (measured in "station-years") doubled twice over, and there was a corresponding increase in publications.  The key institutional development was the foundation in 1778 of the Royal Society of Medicine which, founded in response to a devastating outbreak of cattle plague, had a strong interest in epidemiology.  By the 1780s the Society had established a network of 150 provincial physicians who generated a mass of meteorological observations from all over France.  The organisation  included provision of several calibrated barometers set up by Antoine-Laurent Lavoisier, who planned to extend this system throughout Europe,  The work of co-ordination and collation was undertaken by Father Louis Cotte (1740-1815), who was in charge of the Oratorian  observatory at Montmorency just outside Paris. In 1774 père Cotte had  published a pioneering Treatise on Meteorology, planned as a continuation of Duhamel's "botanico-meteorological" investigations  and stating clearly that the goal should be "the perfection of the sciences of agriculture and medicine".  He made his own observations with the aid of a barometer installed in an unheated room, an alcohol thermometer and an udometer to measure rainfall. The collective findings of the Society  were published in the form of monthly summaries  for each location, based on data reported in standardised forms.  The scope of this work gave Cotte some insight into the geographical extent of weather phenomena and allowed him conclude that given variables might define regional climate.
Nonetheless, he did little with his data, much of which remained unpublished and unstudied until the work of modern climatologists.

Form for meteorological observation, Société Royale de Médicine
http://www.unicaen.fr/histclime/source.php

References

Legrand J.-P. et M. Le Goff, 1992 : Les observations météorologiques de Louis Morin. Monographie n° 6, Direction de la météorologie nationale, tome 1, 36 p, tome 2, 176 p.
http://www.ipgp.fr/~legoff/Download-PDF/Soleil-Climat/Legrand_LeGoff_MeteoXVIIe.pdf

Theodore S. Feldman, "Late eighteenth century meteorology" in  The Quantifying Spirit in the Eighteenth Century ed.Frangsmyr (1992)
http://publishing.cdlib.org/ucpressebooks/view?docId=ft6d5nb455;chunk.id=d0e6035;doc.view=print

Jérémy Desarthe, "Duhamel du Monceau, météorologue", Revue d’histoire moderne et contemporaine 3/2010 (n° 57-3) , p. 70-91
www.cairn.info/revue-d-histoire-moderne-et-contemporaine-2010-3-page-70.htm.

Pierre Caron, Le père Cotte: Inventeur du thermalisme enghiennois  et de la météorologie moderne. Éditions du Valhermeil,  Saint-Ouen-l'Aumône, 2002, 133 p.
Summarised:
http://documents.irevues.inist.fr/bitstream/handle/2042/34782/meteo_2005_48_58.pdf?sequence=1&isAllowed=y