The volume is rare, the only one of his works which the author distributed in the Isle du Palais where he lived. The irregular pagnination suggests that these two sections are intended to appear after his earlier publication  in the same year of  another book called "the beautiful and useful operations that are performed on the proportional compass."  The second section which is the basis of the Gunter rule is titled  the 'Logocanon or Rule Proportional: on which are applied several lines and figures, divided in various amounts and measures, for those who revel in the practicality of divine Mathematics" It has many geometrical diagrams engraved in wood.

In the same year as Napier published his book, [[Henry Briggs]] read it noting "I never saw a book which pleased me better or made me more wonder" and three years later (following closely on the death of Napier), in 1617  published a short initial book Logarithmorum Chilias Prima on decimal logarithms (the idea of which he credited to Napier). The tables ran from 1 to 1000 with an accuracy of 14 decimal places .[^http://www.gap-system.org/~history/Biographies/Briggs.html^]

In 1614 Napier published the first set of logarithms. They were calculated as an exponential function which was neither to a particular base, nor the natural logarithms (to base e) which "Naperian Logarithms" has come to indicate.[^see http://en.wikipedia.org/wiki/Napierian_logarithm^]  Nevertheless, with them it was possible to transform the operations of multiplication and division into operations of addition and subtraction.


In the same year as Napier published his book, Briggs read it noting "I never saw a book which pleased me better or made me more wonder" and three years later (following closely on the death of Napier), in 1617  published a short initial book Logarithmorum Chilias Prima on decimal logarithms (the idea of which he credited to Napier). The tables ran from 1 to 1000 with an accuracy of 14 decimal places .[^http://www.gap-system.org/~history/Biographies/Briggs.html^]

This is the first edition of this book which was published only 12 years after the first publication of natural (or Naperian) logarithms (by Napier in 1614).  Briggs read Napier's book in Latin in 1614 noting "I never saw a book which pleased me better or made me more wonder" and subsequently, in 1617 (following closely on the death of Napier) published a short initial book Logarithmorum chilias prima on decimal logarithms (the idea of which he credited to Napier). The tables ran from 1 to 1000 with an accuracy of 14 decimal places .[^http://www.gap-system.org/~history/Biographies/Briggs.html^]

After further effort Briggs published Arithmetic Logarithmétique 1624, now presenting the logarithms from 1 to 20,000 and again accurate to 14 decimimal places.) In 1625 Wingate published a French edition of Brigg's latest tables.  Together with Henrion's book published in 1626 these two books constituted the first logarithm tables to be published in Europe. 

Meanwhile, a colleague of Briggs, Professor Edmund Gunter, published his Canon triangulorum in 1620 containing logarithmic sines and tangents for every minute of arc in the quadrant to seven decimal places.  In 1624 Gunter published a collection of his mathematical works entitled "The description and use of sector, the cross-staffe, and other instruments for such as are studious of mathematical practise" containing amongst other things the detail of "Gunter's scale" (or "Gunter's rule") which was a logarithmically divided scale able to be used for multiplication and division by measuring off lengths and was thus the predecessor to the slide rule.[^ http://en.wikipedia.org/wiki/Edmund_Gunter - see also http://www.livres-rares.com/livres/HENRION_Denis-_Traicte_des_Logarithmes-95656.asp^]

Dennis (Didier) Henrion  (~1580-1632) was a French mathematician and engineer, who in 1607, was in the service of William of Orange.  He was a prolific author, his best known work being his mathematical memoirs of 1612, his translation of Euclid's Elements over 1614-15 and these books on logarithms.

Henrion's book, published in 1626, brings together these various important developments in England for a European readership.  In it he presents tables of logarithms, based on those published by Briggs in 1624. The volume also contains the logarithmic sines and tangents tables from Gunter's Canon of 1620. 

In a second section (at the bottom of the photograph above), the book  details the design of a logarithmic proportional rule (derived from Gunter's 1624 publication) which was to form the basis for the slide rule along with additional explanations, charts and other elaborations.  The proportional rule could be used directly by means of a pair of compasses to measure off lengths corresponding to logarithms and thus to evaluate multiplications and divisions.

This is the first edition of this book which was published only 12 years after the first publication of natural (or Naperian) logarithms (by Napier in 1614).  Briggs read Napier's book in Latin in 1614 noting "I never saw a book which pleased me better or made me more wonder" and subsequently, in 1617 (following closely on the death of Napier) published a short initial book Logarithmorum chilias prima on decimal logarithms (the idea of which he credited to Napier) from 1 to 1000 with an accuracy of 14 decimal places .[^http://www.gap-system.org/~history/Biographies/Briggs.html^]

After further labour Briggs published Arithmetic Logarithmétique 1624, now presenting the logarithms from 1 to 20,000 and again accurate to 14 decimimal places.) In 1625 Wingate published a French edition of Brigg's latest tables.  Together with Henrion's book published in 1626 these two books constituted the first logarithm tables to be published in Europe. 

The volume is rare, the only one of his works which the author distributed in the Isle du Palais where he lived. The irregular pagnination suggesting that these two sections are intended to appear after his earlier publication  in the same year of  another book called "the beautiful and useful operations that are performed on the proportional compass."  The second section which is the basis of the Gunter rule is titled  the 'Logocanon or Rule Proportional: on which are applied several lines and figures, divided in various amounts and measures, for those who revel in the practicality of divine Mathematics" It has many geometrical diagrams engraved in wood.

Henrion's book, published in 1626, brings together these various important developments in England for a European readership.  In it he presents tables of logarithms, based on those published by Briggs in 1624. The volume also contains the logarithmic sines and tangents tables from Gunter's Canon of 1620.  In a second section, the book  details the design of a logarithmic proportional rule (derived from Gunter's 1624 publication) which was to form the basis for the slide rule along with additional explanations, charts and other elaborations.  The proportional rule could be used directly by means of a pair of compasses to measure off lengths corresponding to logarithms and thus to evaluate multiplications and divisions.

* 1626  Dennis Henrion: Traicté de logarithmes, , règle à calcul  ("Treatise on logarithms, calculating rule") Published in Paris, home of the author, and printed in l'Isle du Palais, 1626. 
Consisting of 2 parts in a volume in-8. 2ff. pp.341-368. 112ff. pp.591-644. 22ff. pp.689-816.   Rare. Covered in flexible vellum.

//1626  Dennis Henrion: Traicté de logarithmes, , règle à calcul  ("Treatise on logarithms, calculating rule")
Published in Paris, home of the author, and printed in l'Isle du Palais, 1626. 
Consisting of 2 parts in a volume in-8. 2ff. pp.341-368. 112ff. pp.591-644. 22ff. pp.689-816.   Rare. Covered in flexible vellum.//

1626  Dennis Henrion: Traicté de logarithmes, , règle à calcul  ("Treatise on logarithms, calculating rule")
Published in Paris, home of the author, and printed in l'Isle du Palais, 1626. 
Consisting of 2 parts in a volume in-8. 2ff. pp.341-368. 112ff. pp.591-644. 22ff. pp.689-816.   Rare. Covered in flexible vellum.

Henrion's book, published in 1626, brings together these various important developments in England for a European readership.  In it he presents tables of logarithms, based on those published by Briggs in 1624. The volume also contains the logarithmic sines and tangents tables from Gunter's Canon of 1620 .  In a second section, the book  details the design of a logarithmic proportional rule (derived from Gunter's 1624 publication) which was to form the basis for the slide rule along with additional explanations, charts and other elaborations.  The proportional rule could be used directly by means of a pair of compasses to measure off lengths corresponding to logarithms and thus to evaluate multiplications and divisions.

This is the first edition of this book which was published only 12 years after the first publication of natural (or Naperian) logarithms (by Napier in 1614).  Briggs read Napier's book in Latin in 1614 noting "I never saw a book which pleased me better or made me more wonder" and subsequently, in 1617 (following closely on the death of Napier) published a short initial book Logarithmorum chilias prima on decimal logarithms (the idea of which he credited to Napier) from 1 to 1000 with an accuracy of 14 decimal places . [^http://www.gap-system.org/~history/Biographies/Briggs.html^]

Meanwhile, a colleague of Briggs, Professor Edmund Gunter, published his Canon triangulorum in 1620 containing logarithmic sines and tangents for every minute of arc in the quadrant to seven decimal places.  In 1624 Gunter published a collection of his mathematical works entitled "The description and use of sector, the cross-staffe, and other instruments for such as are studious of mathematical practise" containing amongst other things the detail of "Gunter's scale" (or "Gunter's rule") which was a logarithmically divided scale able to be used for multiplication and division by measuring off lengths and was thus the predecessor to the slide rule.[^ http://en.wikipedia.org/wiki/Edmund_Gunter - see also http://www.livres-rares.com/livres/HENRION_Denis-_Traicte_des_Logarithmes-95656.asp/^]

This is the first edition of this book which was published only 12 years after the first publication of natural (or Naperian) logarithms (by Napier in 1614).  Briggs read Napier's book in Latin in 1614 noting "I never saw a book which pleased me better or made me more wonder" and subsequently, in 1617 (following closely on the death of Napier) published a short initial book Logarithmorum chilias prima on decimal logarithms (the idea of which he credited to Napier) from 1 to 1000 with an accuracy of 14 decimal places . [^http://www.gap-system.org/~history/Biographies/Briggs.html /^]

This is the first edition of this book which was published only 12 years after the first publication of natural (or Naperian) logarithms (by Napier in 1614).  Briggs read Napier's book in Latin in 1614 noting "I never saw a book which pleased me better or made me more wonder" and subsequently, in 1617 (following closely on the death of Napier) published a short initial book Logarithmorum chilias prima on decimal logarithms (the idea of which he credited to Napier) from 1 to 1000 with an accuracy of 14 decimal places . [1]

Meanwhile, a colleague of Briggs, Professor Edmund Gunter, published his Canon triangulorum in 1620 containing logarithmic sines and tangents for every minute of arc in the quadrant to seven decimal places.  In 1624 Gunter published a collection of his mathematical works entitled "The description and use of sector, the cross-staffe, and other instruments for such as are studious of mathematical practise" containing amongst other things the detail of "Gunter's scale" (or "Gunter's rule") which was a logarithmically divided scale able to be used for multiplication and division by measuring off lengths and was thus the predecessor to the slide rule.[2]

[1] http://www.gap-system.org/~history/Biographies/Briggs.html 

[2] http://en.wikipedia.org/wiki/Edmund_Gunter
 [see also http://www.livres-rares.com/livres/HENRION_Denis-_Traicte_des_Logarithmes-95656.asp]

This is the first edition of this book which was published only 12 years after the first publication of natural (or Naperian) logarithms (by Napier in 1614).  Briggs read Napier's book in Latin in 1614 noting "I never saw a book which pleased me better or made me more wonder" and subsequently, in 1617 (following closely on the death of Napier) published a short initial book Logarithmorum chilias prima on decimal logarithms (the idea of which he credited to Napier) from 1 to 1000 with an accuracy of 14 decimal places . [1] After further labour Briggs published Arithmetic Logarithmétique 1624, now presenting the logarithms from 1 to 20,000 and again accurate to 14 decimimal places.) In 1625 Wingate published a French edition of Brigg's latest tables.  Together with Henrion's book published in 1626 these two books constituted the first logarithm tables to be published in Europe.  Meanwhile, a colleague of Briggs, Professor Edmund Gunter, published his Canon triangulorum in 1620 containing logarithmic sines and tangents for every minute of arc in the quadrant to seven decimal places.  In 1624 Gunter published a collection of his mathematical works entitled "The description and use of sector, the cross-staffe, and other instruments for such as are studious of mathematical practise" containing amongst other things the detail of "Gunter's scale" (or "Gunter's rule") which was a logarithmically divided scale able to be used for multiplication and division by measuring off lengths and was thus the predecessor to the slide rule.[2]

Henrion's book, published in 1626, brings together these various important developments in England for a European readership.  In it he presents tables of logarithms, based on those published by Briggs in 1624. The volume also contains the logarithmic sines and tangents tables from Gunter's Canon of 1620 .  In a second section, the book  details the design of a logarithmic proportional rule (derived from Gunter's 1624 publication) which was to form the basis for the slide rule along with additional explanations, charts and other elaborations.  The proportional rule could be used directly by means of a pair of compasses to measure off lengths corresponding to logarithms and thus to evaluate multiplications and divisions.   The volume is rare, the only one of his works which the author distributed in the Isle du Palais where he lived. The irregular pagnination suggesting that these two sections are intended to appear after his earlier publication  in the same year of  another book called "the beautiful and useful operations that are performed on the proportional compass."  The second section which is the basis of the Gunter rule is titled  the 'Logocanon or Rule Proportional: on which are applied several lines and figures, divided in various amounts and measures, for those who revel in the practicality of divine Mathematics" It has many geometrical diagrams engraved in wood.

  %center% http://meta-studies.net/pmwiki/uploads/Henrion.png

  %centre% http://meta-studies.net/pmwiki/uploads/Henrion.png

  http://meta-studies.net/pmwiki/uploads/Henrion.png