142 JOURNAL OF SCIENCE. 
dicgtyledonous plants; but I obtained several specimens of 
monocotyledonous plants belonging to, perhaps, two species. 
I got some eight different sorts of leaves. One of these 
leaves appears to be identical with that of the Broadleaf 
(Griselinia lucida). ‘Two or three species of pine were also probably 
present. One specimen I obtained had a leaf very like that of the 
Yellow Pine. I was successful in obtaining several specimens of 
fruits of three or four different kinds. : 
Any geologist visiting this place will find it necessary to pro- 
vide himself with a heavy sledge hammer, as the stone is exceed- 
ingly hard, and the blocks are large. Hoping that some geologist 
will make a study of this locality.—I am, &c., 
A, MONTGOMERY. 
“A GREAT MATHEMATICAL QUESTION.” 
(To the Editor N.Z. JoURNAL OF SCIENCE.) 
Si1r,—I beg to thank you sincerely for your review of my 
pamphlet. That I should be accused of not understanding what 
‘energy’ is consideved to be is the last thing that I should have 
thought anyone could bring against me after reading my pamphlet. 
The approval of a journal like what I hope the New Zealand 
JOURNAL OF SCIENCE will be is what I earnestly desire. Will you 
kindly allow me a brief notice of your review, that I may set 
myself right with your readers and with the writer of the review, 
whose good opinion I value. 
On the first page, first line, I say, ‘‘ There are two measures 
of force” (if “‘energy” can be called “‘force’’), and on the next 
page I state as follows :—‘‘ Taking the very same ball, it is asserted 
that (a) the momentum varies simply as the velocity varies, while (0) 
the kinetic energy of the same moving ball varies as the square of the 
velocity.” I do not think it can be said, therefore, that I have 
‘‘ confused” momentum with energy. 
I think the reviewer did not gather in the full meaning of 
Professor Stewart’s remarks, which will be found much amplified 
in his work on the ‘Conservation of Energy.” I however lay 
great stress on the explicit statement of Professor Garnett (page 
8 of pamphlet) in his article on “‘ Energy ’”’ in the ‘‘ Encyclopedia 
Britannica,” ninth edition:—‘‘ Energy may be defined as the 
power of doing work.” The unit of work is a pound weight raised 
to the height of a foot. It is asserted that the time may be 
neglected (pages 11 and 12 of the pamphlet). Ifa pound mass be 
projected so as to rise to a certain height against the force of 
gravity, it is asserted that the energy of the mass, moving with the 
initial velocity it had, is measured by the height to which it rose—the 
amount of work done,—just as if the force of gravity were so many 
feet thick. If the same mass be lifted, no matter how slowly, to 
the same height, it is asserted that no more work is done against 
the force of gravity, though the force of gravity acted for a much 
longer time on the mass in the second case than in the first. Ifa 
steam engine acted for any time, at any rate, the work done would 
be proportional to the time, the rate being uniform. 
Let the pound mass have an initial velocity of 128 feet per 
second. To what height would it have risen in a second if the . 
— ee ee ee ee are 
