January 6, 1923] 
founded at the second restoration of Malacca to Holland 
in 1818. Before Malacca became permanently British 
in 1825, Banks had died and the company had adopted 
another policy. Botanical survey at Calcutta was 
inhibited, and during 1828-32 the company dispersed 
the contents of the Calcutta Herbarium. 
The valuable work accomplished by the Calcutta 
Garden since 1793 in Penang and Singapore, however, 
could not be undone ; as regards Malacca, the reproach 
to England induced by this retrograde policy was 
removed by the private exertions of Griffith during 
1841-44 and Maingay during 1862-69, whose collections 
went to Kew. Largely owing to Griffith’s work, more 
than one-sixth of the plants described by Hooker and 
Thomson in their ‘“ Flora Indica” (1855) are Straits 
Settlements species ; thanks to Maingay, the Straits 
Settlements plants in the two opening volumes of 
Hooker’s “ Flora of British India” (1872-79) rose to 
nearly one-fourth of the whole. During 1874-79, the 
Straits Government organised relationships with the 
western Native States which rendered the latter 
accessible. To assist Hooker the Calcutta Garden 
undertook, during 1881-86, the botanical investigation 
of Pérak, and the Malay Peninsula plants described 
in those parts of Hooker’s Flora issued during 1887-97 
rosé to nearly one-third of the whole. 
In 1888 Mr. Ridley was appointed Director of 
Gardens and Forests, Straits Settlements; in 1889 
King, at the desire of Kew and of the Straits Govern- 
ment, began at Calcutta his “ Materials for a Flora 
of the Malayan Peninsula,” as a supplement to the 
Indian Flora Hooker had already issued and .a pre- 
cursor of the Malay Flora Mr. Ridley has now com- 
menced. By 1go2 King had completed the Polypetale ; 
the Materials of 1889-1902 thus correspond with the 
1872-79 parts of Hooker’s Indian work and with the 
first (1922) volume of Ridley’s Malay flora. Two- 
fifths of the plants in King’s Materials had not been 
reported from the Peninsula when Hooker’s work was 
written ; one-third were new species. Nearly one- 
fourth of the plants now described by Mr. Ridley had 
not been reported from the Peninsula when King 
wrote ; one-seventh are species discovered since the 
Materials appeared. The vegetation of the Penin- 
sula in wealth and variety claims comparison with 
the richest province of the Tropical Rain-Forest 
Region. 
If much has been done to remove what was long a 
reproach to Europe, much, as Mr. Ridley explains in 
his introduction, has still to be accomplished before 
the vegetation of the Malay Peninsula can be regarded 
as fully investigated. A generation hence the additions 
to his Flora may be as extensive as his additions to 
King’s Materials. This only increases our obligation 
NO. 2775, VOL. 111 | 
NATURE > 
to him for placing at the disposal of economic students 
the ripe and exact knowledge of which he has such a 
store, and gives rise to the hope that he may soon 
complete the task so worthily begun. His descrip- 
tions are clear and concise, and he has done well to 
confine his citations of earlier authorities within rigid 
limits ; if there be a fault, it lies in the fact that 
occasionally he has exceeded his own limits by omitting 
references to the works he usually cites. By adding 
text-figures illustrating most of the families discussed, 
he has enhanced the value of the work; Mr. 
Hutchinson’s drawings are so effective that the only 
regret they cause is that they should be so few. Those 
who use the work will not confine their commendation 
to the author and his artist ; if the price be considerable, 
it will at least be conceded that printer and publisher 
alike have fulfilled their duties well. 

Geodetic Levelling. 
Ordnance Survey: The Second Geodetic Levelling 
of England and Wales, z9r2-1921r. Published, by 
Order of the Ministry of Agriculture and Fisheries, 
by Col. Sir Charles Close, Director-General of the 
Ordnance Survey, Southampton, 1921. Pp. 62+46 
plates. (London: H.M. Stationery Office, 1922.) 
17s. 6d. net. 
HE accuracy of modern levelling is a thing which 
always causes surprise when the great number 
of separate operations which enter into the composition 
of a line of any length is considered. 
In the work under notice perhaps the most striking 
result is that the line of levelling starting from mean 
sea level at Newlyn, not far from Land’s End, and 
terminating at Dunbar on the coast of Haddingtonshire, 
generates in all that distance of about 600 miles a 
probable error of only two inches, so that, when it was 
found that mean sea level at Dunbar was ten inchesabove 
that at Newlyn, it was possible to say with confidence 
that the discrepancy was real and due to a deformation 
of the mean sea-level surface and could not be attributed 
to an accumulation of error in the levelling. 
The volume contains an introduction by Colonel 
Sir Charles Close, four chapters by Lt.-Col. A. J. Wolff, 
and five by Mr. H. L. P. Jolly. The operations which 
it describes fall into two separate parts, namely, the 
determination of the mean sea level and the levelling. 
Though the old levelling of England had mean sea 
level at Liverpool as its datum, the height of mean sea 
level had not been determined with accuracy, and a 
new determination was necessary ; it was very desir- 
able also to obtain records whereby the fluctuations of 
mean sea level could be examined and analysed. 
Accordingly, three tidal observatories with automatic 
