Notices respecting New Books. 661 
but from the Incarnation, of Christ (2. ¢. the Annunciation, com- 
monly called Lady Day preceding the Nativity), contends that the 
years should be taken as ordinal, not cardinal, and that the year 
usually called B.c. 1, should be considered to be the first year from 
the initial point of reckoning, so that on its completion one year had 
elapsed. Scientific or astronomical chronologists, when making 
calculations, are compelled to do this virtually by calling the year 0 
which is ordinarily denominated B.c. 1, and when they have finished 
their calculations, restore the B.c. dates to those in the usual system, 
by which the year preceding a.p. 1 is B.c. 1, without an inter- 
mediate year 0,as numerical succession requires. This is why 
Mr. Jordan adopts for his title ‘ Astronomical and Historical 
Chronology,’ which he thinks should be the same, and he dedicates 
his book to the librarians of Florence and Pisa, in the hope that 
they may find in medieval Italian literature further evidence of 
the correctness of his view with regard to the early usage of 
Christian chronology in this way. Although Dionysius Exiguus 
is said to have been a native of Scythia, and was probably Greek 
by nationality, he did his work at Rome (where he died about the 
middle of the sixth century), and his system of chronology was 
first used in Italy. 
As might be expected, in the course of his elaborate discussion 
of the question (taken up, we may mention, at the commencement, 
according to his view, of the present century) the Author furnishes 
us with much subsidiary information with regard to the application 
of the Metonic Cycle and other chronological data. NVe. a ii 
Die Telegraphie Ohne Draht. Von Avcusto RicHI und BERNHARD 
Dessau. Mit 258 eingedruckten Abbildungen. Braunschweig: 
F. Vieweg und Sohn. 1903. Pp. xi+481. 
We had occasion recently to review this work in its Italian edition, 
and as the German issue of it is an exact replica of the Italian 
work, there is little need to do more than merely draw the attention 
of our readers to the existence of the German version. Like all 
Messrs. Vieweg’s publications, it is printed and illustrated im the 
best style. Many of our readers unacquainted with Italian will, 
no doubt, be glad to know that a German version is available. 
Jelineks Psychrometer-Tafeln. Erweitert und vermehrt von J. HANN. 
Neu herausgegeben und mit Hygrometer-Tafeln versehen von 
J. M. Pernter. Fiinfte erweiterte Auflage. Leipzig: W. 
Engelmann. 1903. Pp. xi1+108. 
Tus enlarged set of hygrometric tables should prove very useful 
to meteorologists. The general principles of the wet and dry bulb 
hygrometer, and of de Saussure’s hair hygrometer, are dealt with 
in the introduction, in which the method of using the various tables 
is also clearly explained, and illustrated by several examples worked 
out in detail. Numerous references are given to the literature of 
the subject. 
