Viil 
of the district, reference may be made to two lists of 
birds seen on single days given in the introduction. 
In the first of these the author records having seen 
from the road thirty-four species of birds during a 
drive in the Crieff district; while in the second no 
less than fifty-four are mentioned as having been 
seen by the Duchess of Bedford during a few hours’ 
watching at Meilxleour. 
In the matter of nomenclature the author sticks 
to the scientific names which have been so long in 
general use for British mammals; while in the 
matter of the limitations of genera he likewise 
follows the old-fashioned usage, retaining, for 
instance, the blackbird and the ring-ousel in the same 
genus as the thrush. He will not even accept 
Microtus, in place of Arvicola, for the water-rat and 
its relatives; while as to the proposal to adopt Myotis 
for certain bats, he will have none of it. In one 
point, and one only, we take serious exception to the 
author’s classification—namely, in his reference of 
the slow-worm to the Scincidz, in place of to the 
Anguidz, of which it is the type. 
Were space available, nothing would please us better 
than to refer at length to many of the author’s 
observations on birds and mammals; but editorial 
restrictions peremptorily forbid, so that we can men- 
tion only a few points. 
Two of the most interesting features in the book 
are the maps showing the recent spread and increase 
of the starling and the tufted duck in Scotland. In 
the former case the map 
“shows two distinctly different movements in dis- 
persal of the same, or (?) closely related, races of 
starlings—one from the north and east (and pos- 
sibly from Faroe also), and one by purely increase 
and extension from the south. . In the map of 
the tufted duck’s nesting-dispersal, the advance is 
shown of a species coming for the most part from 
the south by simple increase, but suggesting also 
more than merely a south-to-north direct in- 
crease, and something of a ‘possible arrival from 
the east, along the two very principal routes 
which are followed by migrants at the present 
day.” 
Is there, we wonder, some general unsuspected 
cause connected with these and other recent 
colonisations ? 
Of equal interest are the observations with regard 
to the advent and spread of the squirrel in this and 
the adjacent districts. The author might, however, 
have referred to the fact that the British squirrel is 
certainly a well-defined local race. 
In many cases, as we have seen, the author has 
chronicled the steady increase and spread of birds. 
In other instances, on the contrary, he has the melan- 
choly task of recording their impending extermina- 
tion. ‘“ Meanwhile,’ he writes, for instance, ‘ our 
Ospreys are on the verge of despair; they are in 
anticipation of rapid and final extinction.” Although 
he adds that the resources of civilisation may even 
yet come to their assistance ere the curtain is drawn. 
The goshawk and the kite, although formerly abun- 
dant, now only linger on as stragglers. Mr. Millais, 
who had a pair from a keeper at Rohallion, writes 
that 
NO. 1950, VOL. 75] 
Supplement to “ Nature,” March 14, 1907 
“it is a pity he destroyed them, as they are 
probably the last pair that bred in the country. 
Rohallion, with its great craggy fir-woods, was to 
my knowledge the last stronghold of both goshawks 
and kites.”’ 
With this reference to the end of the kite and the 
goshawk as breeding species, we must likewise 
reluctantly bring to an end our survey of an admirable 
volume. aX. das 
GEODETICAL TABLES. 
Auxiliary Tables to Facilitate the Calculations of the 
Survey of India. Fourth edition. Revised and ex- 
tended, under the direction of Colonel F. B. Longe, 
R.E., by Lieut.-Col. S. G. Burrard, R-E., FARIS 
(Dehra Dun: Office of Trigonometrical Branch, 
Survey of India, 1906.) Price 2 rupees. 
HE growth of the Indian Survey and the improve- 
ments that have been introduced from time to 
time are to some extent mirrored by the increase in 
size and usefulness of the tables, which the depart- 
ment find it necessary to publish. The fourth edition 
of these useful tables ‘‘ to facilitate the computation of 
a trigonometrical survey and the projection of maps 
for India,’’? which fill a tolerably thick quarto volume, 
bears possibly the same relation to the modest first 
edition that the work of the survey of to-day does to 
the work accomplished some sixty years since. In 
that first edition only seventeen tables appeared. Each 
successive issue increased that number, till now we 
have no fewer than sixty-nine tables and six appen- 
dices containing useful matter lilely to prove of assist- 
ance to geographical explorers. 
This new issue and wider employment of tables tells 
also of the changes that have been made in the method 
of projection used in the construction of Indian maps. 
In the olden time the projection was so arranged that 
while the central meridian of a map was a straight 
line, all others were curved and concave to the central 
meridian. This was found to be inconvenient, especi- 
ally when it was required to place two maps together 
so as to form a single map. A modified polyconic 
projection, in which all the meridians are straight 
lines, is now employed. This system, introduced by 
General Walker, will in future be used for all maps on 
the scale 1: 1,000,000 and larger scales. 
With regard to the tables themselves, they neces- 
sarily take the form that long experience has 
approved. This is a sufficient answer to any criticism, 
but to those who have been accustomed to a different 
method of calculation it may seem strange to find the 
logarithms of numbers less than unity affected with a 
negative sign. As doubts have lately been expressed 
of the superiority of the method employed in astro- 
nomical calculations, it is not unimportant to notice 
that so influential a body as the Indian Trigono- 
metrical Survey prefers to retain the use of a negative 
characteristic. There are not, however, many tables 
in which this peculiarity is required. Many tables 
have reference to ‘‘ Graticules of Maps,’’ and give the 
sides and diagonals of areas varying from jy of a 
degree to four degrees, on such scales as are used in 
the department. 
