THE NEW (SO-CALLED) EXPERIMENTS OF OTTO VON GUERICKE ARCHIVES INTERNATIONALES D'HISTOIRE DES IDEES INTERNATIONAL ARCHIVES OF THE HISTORY OF IDEAS

137

OTTO VON GUERICKE

THE NEW (SO-CALLED) MAGDEBURG EXPERIMENTS OF OTTO VON GUERICKE

Directors: P. Dibon (Paris) and R. Popkin (Washington University, St. Louis and UCLA) Editorial Board: J.F. Battail (Paris); F. Duchesneau (Montreal); A. Gabbey (New York); T. Gregory (Rome); S. Hutton (University of Hertfordshire); J.D. North (Groningen); M.J. Petry (Rotterdam); J. Popkin (Lexington) Advisory Editorial Board: J. Aubin (Paris); A. Crombie (Oxford); H. de la Fontaine Verwey (Amsterdam); H. Gadamer (Heidelberg); H. Gouhier (Paris); K. Hanada (Hok• kaido University); W. Kusop (Melbourne); P.O. Kristeller (Columbia University); Elisab• eth Labrousse (Paris); A. Lossky (Los Angeles); J. Malarczyk (Lublin); E. de Olaso (C.LF. Buenos Aires); J. Orcibal (Paris); Wolfgang Rod (Munchen); G. Rousseau (Los Angeles); H. Rowen (Rutgers University, N.J.); J.P. Schobinger (Zurich); J. Tans (Groningen) THE NEW (SO-CALLED) MAGDEBURG EXPERIMENTS OF OTIO VON GUERICKE

by

OTIO YON GUERICKE

Translation and Preface by

MARGARET GLOYER FOLEY AMES

SPRINGER SCIENCE+BUSINESS MEDIA, B.Y.

OTTO Dc GUERICKE

Sercni[s: u PotentiG: :elector: Brandcb: ConJiliarius " Civit.'l.t: ~1.8dcb.Con(ul : THE NE'\oT ( S 0 - C A L"L ED) MAG nEB U R G

E X PER I MEN T S 0 F

OTT 0 VON G U E RIC K E

ONE M P T Y SPA C E

First published by the Reverend Father Kaspar Schott, S. J. Professor of Mathematics at the University of lolurzburg and in the present more complete edition by the author himself who has included a number of additional experiments in the text.

At the same time certain other subjects have been added to this edition concerning the Weight of Air around the Earth, the tfun• dane Virtues, the Planetary System as well as the Fixed Stars and Immense Space which extends within as well as beyond them.

A M S T E R DAM

PRINTED BY JOHANNES JANSSON OF l-lAESBERG 1672 THROUGH THE PRIVILEGE OF HIS IMPERIAL MAJESTY OTTONIS DE GUERICKE EXPERIMENTA Nova (utvocantur) MAG DEBURGICA VB VACUO SPATIO Primum a R. P. GaJPare'Schotto, e Societate Jefu, & Herbipolitan<£ Academia! Mathefeos Profdfore:

Nunc vero ab ipfo AuCl:ore PeifeEtiits edita, varii/que aliis Experimentir auRa.

Q!!ibus accdrcrunt fimul certa qua:dam Ve Aeru Pondere circa 'Terram; de rjrtutibU4~undanu ,& SyJlc• mate Mundi Planetario; fieNt f!J de Stellil Fixls) ae Spatio illo Immel/fa, qllod lam illlra qU41n extra eM funditur.

d M S .T E L 0 D d M J,

Apud J Q ANN E M JAN S SON I U Ml W A E S B E 11. G E) ANNO I 67'l. Cum PrivilegiD S. CiI!f. Majeflatis. Library of Congress Cataloging-in-Publication Data

Guerlcke, Otto von, 1602-1686. [Experlmenta nova (ut vocantur) Magdeburglca de vacuo spatlo. Engllshl The new (so-called) Magdeburg experiments of Otto von Guerlcke ! translation and preface by Margaret Glover Foley Ames. p. cm. (Archives Internationales d'hlstolre des Idees 137) Translation of Experlmenta nova (ut vocantur) Magdeburglca de vacuo spatlo. Inc 1udes Index. ISBN 978-94-010-4888-0 ISBN 978-94-011-2010-4 (eBook) DOI 10.1007/978-94-011-2010-4 1. Physlcal sclences--Early werks to 1800. 2, Astronomy--Early werks ta 1800. 3. Pneumatics--'Early werks ta 1800. 4. Madgeburg experiments. I. Ames, Margaret Glover Feley. II. Title. III, Series. Q155.G9313 1993 500--dc20 93-5121

ISBN 978-94-010-4888-0

Printed on acid-free paper

All Rights Reserved © 1994 Springer Science+Business Media Dordrecht Originally published by Kluwer Academic Publishers in 1994 No part of the material protected by this copyright notiee may be reproduced or utilized in any form or by any means, electronie or mechanieal, including photocopying, recording or by any information storage and retrieval system, without written permission from the copyright owner. TABLE OF CONTENTS

Preface xvii Short Biography of O. von Guericke xxiii

BOOK I THE SYSTEM OF THE WORLD, ACCORDING TO THE MORE COMMON PHILOSOPHICAL THEORIES

Chapter 1. What the World Is, or What Is Usually Understood 1 by the Term, World Chapter 2. The Motion of Stars, the Wanderers or Planets, as 5 well as the Stationary or Fixed Stars Chapter 3. The Two Systems of the Ancients: That Based upon 7 the Presumed Inactivity of the Earth and That Based upon Its Movement Chapter 4. A Brief Resume of the System of the World Based 9 upon Ptolemy's Theory of the Immovability of the Earth Chapter 5. A Revised Pythagorean System of the World 12 Wherein, According to Copernicus, the Sun Is Held To Be in Its Center Chapter 6. The Daily and Annual Movement of the Earth 14 According to Copernicus Chapter 7. Objections of the Astronomers and Natural 15 Philosophers to the Copernican System Chapter 8. Objections to the Copernican Theory from the Sacred 17 Scriptures and their Refutations Chapter 9. The World System According to Tycho Brahe, the 26 Noble Dane. He Assigns the Earth to the Center of the World and the Sun to the Center of the Planets Which Revolve around It (with the Exception of the Moon) Chapter 10. Another System Wherein the Earth Is Situated in the 29 Center of the World and Moves about Its own Axis in the Space of Twenty-four Hours Chapter 11. The Corrected and Improved Copernican Theory of 31 the World Chapter 12. The Sun 31

ix x Table of Contents

Chapter 13. The Sun Spots 32 Chapter 14. Mercury 34 Chapter 15. Venus 35 Chapter 16. The Earth and the Moon 36 Chapter 17. Mars 36 Chapter 18. Jupiter 39 Chapter 19. Saturn and Planets in General 40 Chapter 20. A General Discussion of the Distances of the Stars 41 Chapter 21. The Distance of the Moon from the Center of the 45 Earth Chapter 22. The Size of the Moon 47 Chapter 23.· The Distance of the Sun from the Earth 48 Chapter 24. The Size of the Sun 52 Chapter 25 . The Distances of the Planets from the Earth and 55 their Magnitudes Chapter 26. The Height or Distance of the Fixed Stars from our 57 Earth, According to the Followers of Ptolemy and Chapter 27. The Height or Distance of the Fixed Stars from the 59 Earth According to the Followers of Tycho Chapter 28. The Distance of the Stars According to the Followers 61 of Pythagoras or Copernicus Who Locate the Sun in the Center of the World Chapter 29. The Number of Fixed Stars and the Revelations of 64 Telescopes in this Century as to their Great Extent Chapter 30. The Magnitude of the Fixed Stars 66 Chapter 31. Heaven or the Heavens as well as the Atmosphere 68 and Celestial Matter Chapter 32. The Firmament and the Waters above It, According 72 to the Sacred Scriptures Chapter 33 . The Empyrean Heaven 74 Chapter 34. Are there any other Worlds Beyond This of Ours, 77 and if there Are, Can They be Counted, or Are They Uncountable? Chapter 35. Imaginary Space Outside the World 78

BOOK II EMPTY SPACE

Chapter 1. Why the Author Was Led to Investigate the 83 Chapter 2. Space and Time 84 Chapter 3. Empty Space 86 Table of Contents xi

Chapter 4. Space 89 Chapter 5. The Space Existing between the Earth Bodies Is 91 Commonly Called Sky Chapter 6. Is Space, The Universal Container of All Things, 93 Finite or Infinite? Chapter 7. That Which Is and That Which Is Said not to Be 97 Chapter 8. Is Space, the Universal Container of All Things, 99 Created, or Uncreated? Chapter 9. Infinity, Immensity, and Eternity 102 Chapter 10. Numbers 104 Chapter 11. The Heaven Which Is Called the Abode of the 107 Blessed Chapter 12. The Greatest and the Smallest 109

BOOK III INDIVIDUAL EXPERIMENTS

Chapter 1. Concerning the Origin, Nature, and Characteristics of 111 Air Chapter 2. The First Vacuum Experiment Performed through 114 the Extraction of Water Chapter 3. The Second Vacuum Experiment Performed through 115 the Extraction of Air Chapter 4. The Construction of a Special Type of Apparatus for 117 Producing a Vacuum Chapter 5. The Third Experiment Demonstrating a Vacuum 120 Chapter 6. The Fourth Experiment: the Productidn of a Vacuum 121 through the Extraction of Water from a Glass Vessel Chapter 7. A Fifth and More Accurate Method of Producing a 123 Vacuum Chapter 8. The Sixth Experiment to Obtain the Best Possible 125 Vacuum Chapter 9. Does a Vacuum Exist in Nature, or Not? 130 Chapter 10. Experiments Concerned with Exhalation and 134 Fermentation Chapter 11. The Experiment in Which Clouds and Wind and the 135 Colors of the Rainbow Can Be Produced in Glasses Chapter 12. Fire in a: Vacuum 138 Chapter 13. An Experiment in Which Air Is Consumed by Fire 139 Chapter 14. Light in a Vacuum 140 xii Table of Contents

Chapter 15. Sound in a Vacuum 141 Chapter 16. Experiments Performed with Animals in a Vacuum 143 Chapter 17. The Construction of a Kind of Hydraulic-pneumatic 144 Apparatus Which Can Be Used not only for Carrying out Numerous Experiments but also Used as a Source of Mental Recreation and Study Chapter 18. The Use and Operation of the Aforementioned 145 Apparatus Chapter 19. A New Discovery through the Use of this Apparatus 149 Which Indicates the Weight of the Atmosphere Chapter 20. Other Experiments of this Kind Which Demonstrate 151 the Weight of the Atmosphere as well as the Limit to Which'Aversion of a Vacuum Extends Chapter 21. Concerning the Weight of Air 155 Chapter 22. How to Determine the Pressure that a Cylinder of 157 Air of any Given Circumference Exerts Chapter 23. The Experiment Demonstrating that as a Result of 160 Air Pressure, Two Hemispheres Can Be Joined Together in Such a Way that They Cannot Be Separated by Sixteen Horses Chapter 24. A Further Experiment Wherein the Hemispheres 163 Which Could not Be Drawn Apart by Twenty-four Horses Are Separated by the Admission of Air Chapter 25. Another Experiment Wherein It Is Shown that the 165 Aforementioned Hemispheres Can Be Separated by a Weight Chapter 26. Another Experiment Demonstrating that All Vessels 167 Can Be Compressed and Broken by Air Pressure Chapter 27. A Glass Vessel Which Can Forcibly Pull More than 168 Twenty, indeed Fifty or More Strong Men Chapter 28. An Experiment to Raise a Great Weight 171 Chapter 29. An Experiment Employing a New and Heretofore 172 Untested Airgun Chapter 30. Experiments Which Show how Air Pressure Varies at 174 Different Altitudes Chapter 31. Experiments Showing how Air Pressure Fluctuates 176 According to the Weather Chapter 32. The Cause of Suction 177 Chapter 33. Experiments Concerned with the Expansion and 178 Condensation or Compression of Air Chapter 34'. An Experiment Demonstrating Proof of a Vacuum 181 through the Descent of Mercury in a Glass Tube Sealed at the Top Table of Contents xiii

Chapter 35. Common Objections to the Existence of a Vacuum 183 and their Refutation Chapter 36. The Opinions of the Reverend Kircher and Zucchi at 187 Rome, as well as Father Cornaeus, Professor at the University of Wtirtzburg, Concerning the Magdeburg Experiments Chapter 37. A New Thermometer, so-called Magdeburg 189

BOOK IV MUNDANE VIRTUES AND OTHER ALLIED SUBJECTS

Chapter 1. A General Discussion of Mundane Virtues 193 Chapter 2. The Incorporeal Impulsive Virtue of the Earth 195 Chapter 3. The Nature and Characteristics of the Impulsive 198 Virtue Chapter 4. Experiment with a Globe Freely Suspended in Water 202 Chapter 5. The Conserving Virtue of the Earth 204 Chapter 6. The Expulsive Virtue of the Earth 206 Chapter 7. The Directing Virtue of the Earth 208 Chapter 8. The Difference between the Conserving and 211 Directing Virtue of the Earth Chapter.9. The· Turning Virtue 212 Chapter 10. The Sound-producing and Echo-producing Virtue 213 Chapter 11 . The Heat-producing Virtue 218 Chapter 12. The Light-producing and Coloring Virtue 219 Chapter 13. The Nature and Characteristics of Vision 222 Chapter 14. The Difference in Appearance between Stars at 224 Greater and Lesser Distances Chapter 15. The Experiment Wherein these Aforementioned 227 Important Virtues Can Be Excited through Rubbing on a Sulphur Globe Chapter 16. Other Corporeal and Incorporeal Virtues 232

BOOK V THE SPHERE OF LAND AND SEA AND ITS COMPANION, THE MOON

Chapter 1. The Sphere of Land and Sea, or the Earth, and Its 235 Size Chapter 2. The Size of our Sphere of Land and Sea Relative to 237 the Planetary System xiv Table of Contents

Chapter 3. The Earth Is Composed of an Infinite Variety of 238 Things both Externally and Internally Chapter 4. The Earth Spirit 242 Chapter 5. The Sea and Its Tides 244 Chapter 6. The Air Surrounding the Earth and the Elementary 247 Fire, that Has Been Postulated Chapter 7. The Height of the Air around the Earth 249 Chapter 8. An Observation Made in the Carpathian Mountains 250 in Hungary by David Frolich Which Seems to Make a Significant Contribution to the Existing Opinion about the Height of Perceptible Air and Stratification Chapter 9. The Stratification of the Atmosphere 252 Chapter 10. The Refraction of Air and the Consequent Difference 254 in the Appearance of Stars, both as to their Location and Size Chapter 11. The Eccentricity of the Sun and Moon 257 Chapter 12. The Motion or Circulation of the Air 260 Chapter 13. The Sphere of Earth and Water Does not Lie at Rest 261 in the Air Chapter 14. The Sphere of Earth and Water Is not in the Center 263 of the World Chapter 15. The Rotation of the Earth 266 Chapter 16. "Latio" or the Forward Motion of the Earth 268 Chapter 17. The Moon 272 Chapter 18. The Appearance of the Moon and Its Spots 274 Chapter 19. The Forward Motion of the Moon 276 Chapter 20. The Moon's Motion 277 Chapter 21. The Conjunction and Comp,arison of the Moon with 278 our Sphere of Earth Chapter 22. The Distance and Size of the Moon 280 Chapter 23. Are There or Are There not Animals on the Moon? 282 Chapter 24. Eclipses 283 Chapter 25. The Destruction of the Earth 285 Chapter 26. Appendix to this Fifth Book. Comets 287

BOOK VI OUR PLANETARY SYSTEM

Chapter 1. The World, What It Is, and What Is Included in the 309 Term, in this Treatise Table of Contents xv

Chapter 2. In What Sense the World Is One Body and Why It 311 Should Be Termed a Unity Chapter 3; The Forward Mot jon of the World 312 Chapter 4. The Peripatetic Concept of the World 314 Chapter 5. The Motion of the World According to the Followers 315 of Tycho Chapter 6. The Movement of the World as Set Forth by the 316 Author and in Part by Certain other Writers Chapter 7. The Earth Bodies 318 Chapter 8. The Sun 319 Chapter 9. The Size of the Sun and Its Distance from the Earth 322 Chapter 10. The Wandering Stars or Planets 327 Chapter 11. The Forward Motion of the Planets 329 Chapter 12. Planetary Motion 331 Chapter 13. The Distance of the Planets 331 Chapter 14. The Size of the Planets 334 Chapter 15. Are there Animals on the Planets? 335 Chapter 16. The True System of the World 341 Chapter 17. The Boundaries of our World 345

BOOK VII THE FIXED STARS AND THE BOUNDARY WHICH CONFINES THEM

Chapter 1. The Distance of the Fixed Stars from our Earth or 351 rather from the Sun Chapter 2. The Size and Number of the Stars 357 Chapter 3. The Fixed Stars and What They really Are 361 Chapter 4. Father Kircher's Opinions concerning the Fixed Stars 365 along with our own Remarks Chapter 5. The Limit or Outermost Boundary of the Stars 382

Index of Subjects 389 PREFACE

The contemplation of nature, to which the blessed Basilius bears witness, is a threshold of joy, an eternal source of pleasure for the spirit, a portal of tranquility, a bridge from the celestial to the earthly and the peak of man's happiness. Attaining this, the soul seems to be aroused, as it were, from a deep lethargy and enters a region of light, forgetful of self, and assumes the role, not so much of a man touched by divinity, as that of an earth-bound deity. That well-known verse, indeed, is true:

"If mortal souls were to understand the innermost workings of the cosmos, Royal power and might would be nothing more to them than mean• ingless froth." To attain such knowledge of nature, the art of oratory, an elegance of speech, or the ability to debate incisively are of little account. "For in seeking this a thousand Demosthenes, a thousand can be laid prostrate by a single man of mediocre talent who has seized upon a better way to find the truth. Such a hope, therefore, must be removed: for indeed, men, more learned and superior to us in book-learning, will be found who, to the shame of nature itself, can make that which is, in fact, false, true." Galileo, Dialogus Cos• micus, page 35. Therefore theories which are demonstrated by experiment and visual perception must be preferred to those derived from reasoning, however probable and plausible, for many things seem true in specu• lation and discussion which in actual fact defy reality.

"It follows from this that all science is empty, deceptive, and point• less unless it is supported by experiment. What inconsistencies other• wise successful and perceptive scholars bring forth without its help! It is experimentation that dissolves all doubts, reconciles difficulties, is a unique teacher of truth, furnishes a torch in darkness and in• structs us how to determine the true causes of things by disentangling knotty problems." Kircher, Ars Magnetica, page 570. . Thus scientists who rely upon their conjectures and hypotheses alone, repudiating experimentation, can make no conclusive state• ments about the nature of the world, for when man does not rely

xvii XVlll Preface upon experiments, he often wanders so far from the truth as the sun which we see is distant from the earth.

Gilbert Clerke very recently acknowledged this fact in the Preface of his book, De Plenitudine Mundi, where he writes: "Natural science at one time was dependent upon debatable and dubious assertions, (expressed in sesquipedalian words), designed to deceive true scientists and other scholars rather than to enlighten them.

* * *

"So it has happened that a man who, thanks to his argumentative powers would acquire for himself a meaningless reputation for knowledge and would be looked upon as an outstanding scholar, a man who knew very little about himself but seemed to feel he had much more insight than anyone else, in the paroxysms of his mad• ness, would chatter about whatever nonsense came into his head. "Finally, however, there shone forth, with 's help, certain men of more exalted talents who led the way in a new kind of research, using both reason and experimentation in combination. "From these men there was conceived the hope that scholars would not embrace some sort of shadow or delusion of truth, but truth itself and that, putting aside controversy, natural science would come to be allied with mathematical science. This is not the task of one age nor a single individual to bring to fruition, but neither need we doubt (when one scholar after another supports this same kind of reaearch) that finally with the new mysteries of nature being removed daily and the dark night of errors dispelled, truth, in all its purity, (insofar as the innate weakness of humankind allows) will appear and the marriage torches lighted. "Indeed, in the present state of affairs, it pains me that up to this time, I have seen a certain need for dissention and arguing back and forth while the leaders of this new science dispute about the composition and plenitude of the world and trip over the threshold of knowledge, etc." Because, in truth, scholars have sharply disputed with one another for a long time the question of the vacuum (does it exist or not? or what is it?) and each one has defended his theory like a determined soldier defending a stronghold against an attacking enemy, for this reason I felt a burning desire to investigate the truth of this question which has been a source of dispute, not being able to lay my feelings Preface xix to rest nor extinguish them until I should find time to carry out an experiment involving the vacuum. I performed this experiment in a number of ways and my efforts were not unrewarded: indeed, I designed several pieces of apparatus to prove the existence of that vacuum whose existence had always been denied. Later on, when I had been sent on behalf of the state to the Imperial Diet being held in in 1654 several enthusiastic followers of these kinds of investigations had heard about my afore• mentioned experiments: they succeeded in convincing me to demon• strate some of them and I endeavored to do this insofar as I could, considering the limits of my capabilities. At the conclusion of the meetings of the Diet and when it was breaking up, my experiments were brought to the notice of his Imperial Majesty as well as the Electors and several Princes who were on the point of leaving but wished to see my experiments demonstrated before their departure. I could not refuse their request under the circumstances. These experiments were of particular interest to His Eminence the Noble Elector Johann Philipp, Archbishop of Mainz and Bishop of Wiirzburg, who of all the spectators present, persuaded me to make a similar piece of apparatus for himself. Because of the limitations of time, however, this apparatus could not be reproduced by my workmen and so, at the request of his Eminence, I handed over the experimental instruments I had brought with me to Regensburg for a financial consideration. As soon as the Reverend Fathers of the and the professors of the public University of Wiirzbtirg, under the chairman• ship of the same Eminent Elector, had verified these experiments of mine, they wrote out a draft of their findings and communicated them to the scholars in Rome and elsewhere and at the same time sought their opinions. Among this group of particular importance was the Reverend Father Kaspar Schott, Professor of Mathematics at the same university, who wrote me regarding the experiments and sought more information about them. Ultimiltely he added, as an Appendix to his book, De Arte Mechimica Hydraulico-Pneumatica, published in 1657, these "Experimenta Nova" of mine and called them "Magdeburgica:" these were set up in type so that they might be available for many to read and study. After these experiments had been exposed to public scrutiny, many others that I had hitherto carried out were added. These, in turn were published by the aforementioned Father Schott in Book I of Technica Curiosa which dealt with the Magdeburgica Mirabilia, xx Preface published in 1664, together with the Antiqua Experimenta Magdebur• gica and the Nova Experimenta Magdeburgica. In addition to Father Schott, other scholars were found who wrote on this same subject and, indeed, almost everyone who saw the apparatus and the results stemming from the experiments was seized with astonished admir• ation. And just as the Reverend Father Schott attests in the Foreward to his Technica Curiosa, page 3, (and other places as well), "I do not hesitate to speak openly and declare without qualification that I have never seen nor heard of any experiments of this kind more worthy of admiration nor read nor even imagined such, and I do not believe that the sun ever shone upon anything like them from Time Immemorial. And I might add, this is the judgment of powerful princes and learned scholars as well, with whom I have been in communication as regards these experiments, etc." So these feelings will be made abundantly clear by everyone else everywhere who has brought forth treatises on this subject. Although, in fact, it was never my intention to have my experi• ments printed and published, nevertheless the very diverse judg• ments of the "De Vacuo" of which some approve and others attack the contents, in order that no one could be surprised by so many different and often remarkably confused concepts and at the same time satisfy those who urgently asked for a clarification of these experiments, I undertook the publication of the treatise, De Spatia Vacuo in its entirety for its advantage in providing a deeper under• standing of the field of natural science. I finished the work on the 14th of March, 1663; I did not seek to correct nor refute the numerous and frequently inconsistent opinions of philosophers (except briefly in Chapters 35 and 36 of Book III where at least the usual and typical objections of the Reverend Fathers and professors, who are named explicitly in the Appendix of Schott's Ars Hydraulico-Pneumatica, are discussed). Indeed, such a treatise would be too long-winded and tedious for the reader to encompass. Rather its aim is to recall from ingrained and poorly conceived imaginings all who do not labor under preconceived opinions but regard the experiments dispassion• ately and weigh them on the fair scale of truth, having acquired from them rich experience and knowledge. Indeed, when there is evidence from facts, words are not necessary. One need not dispute and take up arms against an opponent who denies experiments that are completely reliable; let such a one keep for himself his own opinion and dig in the dark like a mole. An exact science does not march into battle but celebrates its victory and rests in the deep tranquility of truth. Other branches of science, however, are subject to contro• versy because they are devoid of the rational certitude in which an Preface xxi exact science is rich. So it comes about that the human spirit, after it has wandered for a long time in the circle of arts and science finally comes to find rest in the certain knowledge of an exact science. As for the form in which this treatise is presented, it is not intended to be eloquent nor elegant in verbiage: however, if there is any fault in my use of words, I should like to be excused, because weare concerned with facts, not words which are only in the service of facts rather than the other way around. Indeed, all things could not be adequately described verbally, but often for the sake of brevity, had to be omitted or reduced to the common idiom as the old proverb says, "Speak with many words but think with a few." And although this book had been completed seven years ago, as I mentioned, I was hindered in its publication in part by illness and in part by a series of business commitments. This work would have remained in the desk for a still longer time, however, had not several distinguished men, together with Lukian, thinking it a wretched state of affairs that knowledge was being drained from the books alone without being substantiated by any published experiments, put an end to my vacillation, encouraging me not to hesitate and refuse any longer in bringing out this work for general use. For this reason I did not want to disregard their wishes for its publication. Just as all things are not pleasing to everyone, so one can easily surmise that opponents will not be lacking, as the proverb says, "Let no one be persuaded otherwise, for he is going to have both enemies and followers who embarks upon great undertakings." And indeed, (to quote from Seneca), there is no mortal man who does not suffer from some sort of ignorance; "this is an age-old ill of mankind. For as often as a man errs, he errs like a man. To reproach a man for his erring, however, is to reproach humankind itself. " For this reason, one should not expect to be so fortunate as to be able to bring forth any work that is flawless . Indeed, for our part, we sometimes commit errors in pointing out the faults of others and in the same vein must readily accept the criticism thoughtful and honest men make of results found in this work which are not substan• tiated by experiment. In this situation, when we learn or have to admit another conclusion that is better and perhaps correct, we must be ready to recognize the truth. Before all else, however, it is our wish that the contents of this work be encompassed by the cloistered walls of natural science and not slip out from these confines into other fields that are perhaps mixed with faith or belief: rather, this treatise must be limited by the principles of natural science alone made manifest by experimen- XX11 Preface tation. But should some thoughtless or inadvertent remark slip out contrary to our intention, however, we should like to retract this statement herewith. We grant to everyone the freedom of dissent but for our part we are prepared to follow truth rather than agree• ment for the sake of harmony. As for the rest, we believe that there will be no lack of keen and perspicacious minds, being stimulated by my experiments to arrive at perhaps better and deeper insights, who are going to undertake this work at some future time. And so farewell, gracious reader, and regard our efforts in good part.

Written in Magdeburg, the 14th of March, 1670

DEDICATED TO THE "EXPERIMENTA NOVA MAGDEBURGICA" OF THE MOST DISTINGUISHED AND EXCELLENT GENTLEMAN, OTTO VON GUERICKE

To delve into the manifold mysteries of nature is the task of an inquiring and fertile mind. To follow the tortuous paths of nature's wondrous ways is work more difficult and not designed for everyone. You, Distinguished Sir, Magdeburg knows as its Burghermaster as well as an outstanding researcher in the field of science. Whether one speaks with you informally or studies your work alone, he soon will confirm your genius openly and without a feeling of doubt. . May I make a small joke? While you prove quite clearly that a vacuum exists in your Book, there is not a vacuum to be seen!

In this insignificant poem, I have set down no insignificant proof of my eternal gratitude to my most excellent patron with warm wishes for a long life. Johannes von Gersdorf . Nobleman of Lausitz SHORT BIOGRAPHY OF O. VON GUERICKE

Guericke (Gericke), Otto von (born in Magdeburg, Germany, 20 November 1602; died in , Germany, 11 May 1686.

Otto Guericke, the son of Hans Gericke and Anne von Zweidorf, was a descendant of an aristocratic family of Magdeburg who had occupied positions of authority and prominence there for three hun• dred years. Destined to enter political life as a young man, he was registered as a student in the Faculty of Arts at Leipzig from 1617 to 1620. When the opening campaign of the Thirty Years War threatened to engulf Leipzig, however, he was sent to Helmstedt, in Brunswick, to attend the university there. Later he studied law at Jena in 1621 and 1622, continuing his studies in this field in Leyden where he also attended lectures on astronomy, mathematics, and . Upon completing his university studies, Guericke returned to Mag• deburg and as a young man of twenty-four (1626) was elected to the City Council and elevated to the Bench of Magistrates. Four years later he assumed the additional duties of City Contractor in which capacity he supervised the building, maintenance, and defense of the city's fortifications. Little is known of Guericke's personal life except that in 1626 he married Margarethe Alemann, the mother of his only surviving child, a son also named Otto. Several years after her death in 1645 he married Dorothea Leutke, but was again left a widower. Shortly after his second wife's death, he and his son went to live with Guericke's mother on their manorial estate. In 1681, after he had retired from public office, he went to live in Hamburg with his son who had been elected a magistrate of Brandenburg. He spent the rest of his life there until his death in 1686. Because Magdeburg was regarded as a city of considerable stra• tegic importance, it was inevitable that it playa significant role in the Thirty years War which was spreading over Germany. Inasmuch as Guericke was vitally involved in the affairs of Magdeburg at this time, particularly as supervisor of the fortifications, he was an important participant in the two successive sieges of Magdeburg which resulted in its destruction in 163l. Guericke left Magdeburg at this time and joined the army of Gustavus Adolphus of Sweden in his victorious sweep through Ger• many. He served with the Swedish forces as Quartermaster General and Chief Siege Engineer when they laid siege to the city of Erfurt.

xxiii xxiv

Four years later he found service with the Saxon Army. In these dual capacities Guericke was able to continue to serve his native city by acting as envoy to the changing occupation powers. He returned to Magdeburg after these foreign commitments and devoted much of his time and resources to the rebuilding of the city. Feeling respect and gratitude for his devotion, his fellow citizens sent him to Dresden and Leipzig for three years where he helped formulate thc treaty which brought peace to Germany. From 1642 until 1666 diplomacy consumed much of his time as did his duties as Burghermaster, a position he held for twenty years until 1676. He was likewise elevated to the nobility by being ap• pointed Counsellor to the Elector of Brandenburg. It was at this time that Guericke assumed the noble "von." Throughout his varied philanthropic career, however, beginning in 1632, Guericke had devoted his brief and limited leisure time to scientific experimentation. Thus, congruent with his duties as diplo• mat, he attended international congresses and princely courts where he could take part in the exchange of scientific ideas. He was able to present some of his own experiments on several occasions at Regensburg in 1653-54 and again in 1663 at the court of the Great Elector of Berlin. Although the politically important statesmen and scientists who comprised his audiences willingly examined and evalu• ated his work and found it worthy of notice, nonetheless they ques• tioned its validity. He was regarded, for the most part, as an enthusi• astic amateur rather than as a scholar to be reckoned with, because he was neither affiliated with a university nor was ·he a member of any learned society.