87 
only in the apartments of ‘the King, Queen, and Lady Mary ;” and 
of its coming into general use about the time of Charles I., 1625, 
The story that a citizen of London was executed for using coal ccn- 
trary to statute had no foundation in fact ; the nearest approach being 
the pains and penalties incurred in Edward I.’s reign (1806), ‘‘ when 
all who burnt sea-coals, against the proclamation, within the City or 
part adjoining thereto it, were to be punished for their first offence by 
great fines and ransoms, and for their second by the demolition of 
their furnaces and kilns wherein they burnt sea-coals.” 
The true vegetable origin of coal was not only determined by 
observing the conditions under which it occurred, but by the fossil 
remains associated with it and by the results of microscopic examin- 
ation. These showed that coal was simply vegetable matter, altered and 
compressed—in other words, vast accumulations of trees and various 
plants, which either grew on the spot where the coal was now found or 
were brought down by vast rivers to a great estuary, where it accumu- 
lated, Some idea of the enormous amount of vegetation necessary to 
produce the coal measures might be inferred from the fact, that a 
square mile of forest land covered by 20,00u trees, each containing on 
an average two cubic yards of solid firewood, would only be equivalent 
to about an acre of coal 6ft. thick (10,000 tons), or to three acres of 
turf of the same thickness. 
In connection with the vegetation which helped to form the coal 
one thing was most striking : the almost absence of that kind of wood 
which was characteristic of the forest trees of the present day, and the 
enormous preponderance of ferns and allied plants, such as clubmosses 
and calamites. Very few, if avy, of these plants retained their form 
sufficiently to admit of a satisfactory demonstration of what they were 
absolutely like ; but fronds of ferns more or less mutilated, detached 
roots and stems, with here and there cones or nuts, fragments of 
- flowers, and fructification, helped to determine some of the orders of 
plants constituting our stores of cval. 
No very safe conclusions respecting the climate of the coal period 
could be deduced, for, while the ferns would imply a moist atmosphere, 
the conifers were found in hot and dry and cold and dry climates as well 
as hot and moist and cold and moist climates ; but, by a comparison of 
the relative proportion of ferns and conifers, with the other orders of 
plants in any known district, it was found that New Zealand presented 
