176 
NAGORE 
| DECEMBER 24, 1896 
the rate of 8-13 per hour, of which only a small proportion still 
were Leonids, and by Mr. Blakeley at Dewsbury, who noted, 
from 12 to 44 a.m., with two hours of quite clear sky at last, 
forty meteors, never appearing faster than fourteen per hour, 
among which were twelve Leonids with an hourly rate never 
exceeding six. Four or five of the Leonids were very bright, 
and their radiant-point was well defined at 150°, + 24°; but the 
whole display fell considerably short in brightness of that 
observed in 1895. ! 
Perhaps the three close-following meteor-showers may all 
have fallen a little later this year than the figure represents 
them ; but the first few hours of watches on the mornings of 
November 13 and 14 should at least, as the diagram shows, have 
been (as they were) both slenderly productive times, while a 
bright meteor-shower should have prevailed (as it did, rather 
vividly) on the morning of November 15. On last year’s 
November dates the case was different, a rather bright array of 
Leonids being seen on the morning of November 14, followed 
by a smaller one on November 15, while after the latter date a 
generally clouded state of the sky in England prevented further 
observations, At Bridgwater, on November 14, Mr. Corder 
mapped eleven Leonids between 2 and 4} a.m., and found their 
radiant point at 152°, + 23°. Five or six Leonids were recorded 
here between 12 and 3 a.m. on that morning, with a radiant- 
point at 151°, + 23°, to which were also traced the paths of two 
Leonids mapped between 1 and 24 a,m. on the next morning of 
November 15, when the shower seemed to be -passing off, and 
when clouds on that and in the next night’s watch prevented a 
complete view of the shower from being obtained at Bridgwater, . 
and generally in England. The spectacle was thus most promin- 
ently seen last year on the mornings of November 14 and 15, 
while it was this year most conspicuous on the morning of 
November 15; and this agrees with this trial-figure’s indication 
that the early and middle branches of the shower should have 
occurred at favourable morning hours on November 14 and 15 last 
year for English observations ; but at such late hours this year, 
as to be only weakly visible in a few slight foretokenings on 
November 13 and 14, compared with the full brightness of the 
after-shower brought into view on the morning of the 15th by the 
same advance in hour together of all the three members of the 
triple concourse. If the present positions and durations, then, 
of these component showers may be assumed to have been de- 
picted in the figure with approximate correctness, a full view of 
the end and middle portions of ¢he first shower beginning to 
appear in the next two years, 1897 and 1898 after midnight 
{a.m.) on November 14, will afford means of comparing in 
strength and brightness those phases of the leading shower with 
the middle and early parts respectively of the a/ter-coursing one, 
then still well visible on November 15, to gauge their relative 
extents in length and width, and the relative looseness or com- 
pactness of their structures, which may perhaps not offer them- 
selves again so favourably for some years. 
It will also be very useful in coming years’ watches for these 
detached clouds of fragments from the meteor-comet, to note 
exactly the hours of the watches kept, the states of sky and 
moonlight, with the numbers and brightnesses of the Leonids 
and sporadic meteors seen, to enable a true distinction to 
be drawn between bordering diffuseness of the streams, and 
really distinct branch-currents or offshoots from the meteor- 
cloud ; for between 4 and 6 a.m. on November 17, and from 
2 to 5 a.m. on November 18, last year, Mr. Corder found true- 
pathed Leonids almost as numerous (11 out of 22 meteors, and 
$ out of 30 meteors) compared with the sporadic shooting-stars, 
as on November 14 (11 out of 26 meteors), from 2 to 4 a.m.; 
while on the previous morning of November 13, from 2 to 44 
a.m. only 3 or 4 Leonids were seen among 18 meteors ; show- 
ing that both gaps and condensations reaching to considerable 
but as yet not fully determined distances from the main streams 
exist to either side of them, of which the extents and the changes, 
or the fixity of distribution would be very interesting particulars 
of their modes of assemblage to endeavour to trace out by 
observations. 
On the morning of the 27th ult., in clear sky, between 14 and 
3 a.m., seven small meteors were recorded here, two of which, of 
1 The English Mechanic, November 27, 1896. At Funchal, in Madeira 
(th. 8m. W. long. from Greenwich), Leonids were seen falling at the half- 
hourly rates of 6, 9, 6 in half the sky, from 4} to 6 a.m. (about 5.40 to 7.10 
a.m., Greenwich time), on November 14; the similar rates between 2 and 
4% a.m., in equally clear sky, having been only 3, 1, 1, 2 and ‘1 in half an 
hour.—Letter from Mr. W. Anderson, in the English Mechanic, December 
rx, 1896. Note, December 15.—A. S. H. 
NO. 1417, VOL. 55] 
Ist and 2nd mags., and orange colour, at 2, and 2.42 a.m., be- 
tween cand o Honorum, radiated with short slow courses from 
between 8 and 6, and from near y Andromede, and were evi- 
dently fore-shortened Andromedes; but the first of them, at 
least, was quite as erratic from the true centre, near y Azudro- 
mede of the Bielan shower, as the tracks through Cancer, 
Hydra, and Leo Minor of the recent showers of Leonids have 
been from their native shower’s true radiant-point. The horary 
scarcity of these small Andromedes on their annual date this 
year, showed that no brisk Biela meteor-shower was then in 
active progress. On the two evenings immediately preceding 
and following this short morning watch, the sky here was quite 
overcast. A. S. HERSCHEL, 
Observatory House, Slough, December 9. 
The Force of One Pound. 
Dr. LopGcE has some right to complain of the friendly post- 
card. I wanted the Powndal difficulty to be threshed out in 
public, and we had just been writing to each other about it, 
but I quite forgot that my post-card might give him the wrong 
notion that my general remarks referred to him. Dr. Lodge 
knows that the real question before us concerns the Poundal ; 
he knows that his advocacy of it has helped to maintain that 
unit in its academic position, and yet he now leaves its defence 
to others. He professes his love for all units, and attacks the 
poundalists and the poundists impartially, for suggesting ad- 
herence to any system in particular. This is better than his own 
maintenance of the Poundal, and I hope that it presages a com- 
plete change of front. His maxims are of the best: ‘* Urge 
clearness of idea and accuracy of speech on all who deal with the 
junior student. These should not call different things by the 
same name...” But what if they continue to do so? He 
himself often uses ve/oczty when he only means sfeed. 
A pound of force, a pound of stuff, the inertia of a pound ; 
here are three very different things all with the same name. When 
the chemist tells us that there is the same quantity of matter 
after as before chemical combination, what does he mean? 
He means that the wezght of it is the same; the force of attrac- 
tion by the earth. A certain amount of oxygen is equivalent in 
a certain property (its weight), to a quantity of hydrogen, and he 
says that he will call the quantities equal. Certain quite 
different amounts of them are egz¢va/ent in another property ; 
he has exactly the same reason for calling these other amounts 
equal. A ton of iron is equivalent in a certain property to two 
ounces of gold. Why not call these amounts equal ? 
A pound of gold is no more the same as a pound of iron, 
because their weights and inertias are the same, than two 
chairs are the same as one table because they may be equal in 
value. I hope that Prof. Fitzgerald may be induced to say 
something on this head, the ‘‘huggermugger” of confounding 
quantity of matter with inertia; for I think with him that this 
is what produces far more confusion in the minds of students 
than the use of many different units for things of the same kind. 
The practical engineer has uncommon good sense, he hates the 
Poundal, and I think that Prof. Fitzgerald is right when he 
says that it is not merely because it is a new unit, but because it 
is founded on ‘‘huggermugger.” Let Dr. Lodge read Mr. 
Jackson’s letter which followed his own. He will see that 
Mr. Jackson cannot comprehend how anybody can avoid using 
the pound of stuff as a fundamental unit, and how it must be 
innate perversity which causes engineers to adopt as their unit 
of inertia (or mass, as they have unfortunately to call it), the 
inertia of a body to which the unit force gives unit acceleration. 
This is the fruit of the Poundal ; no doubt its inventor thought 
of inertia. Mr. Jackson thinks of quantity of stuff, which is a 
conventional or metaphysical idea. 
The standard units of time, of force, of inertia ; we can only 
keep them in indirect ways. Assuming that waste is prevented 
and that the weight and inertia of a certain body measured 
under the same circumstances at the same place are always the 
same, any standard body with proper comparing instruments 
gives us our standards of force and inertia. The instru- 
ment for comparing forces is ready to hand, a good 
weighing balance. There is no instrument which can be 
relied upon for comparing inertias, so we fall back upon 
an indirect method, assuming that inertia at any place 
is proportional to weight. But it is to be noticed that all 
our practical acquaintance with inertia and with what we call 
quantity of matter is based upon our measurement of wezght, of 
