306 
poife; and + = the velocity of the wind. 
im feet per fecond: 
b 
Then Fi is the force exerted againit t fuperfi- 
cial foot ef the plane; and, from the above, as 
x? 005 
> x23 hence Sie 

nis 
3 !202:: y OF — 
3 a ; 
— and x = go, /—» a general rule | 
aa ? a —>s5 _—_— 
ci ee 44 3a 
In the prefent-ca’e, x = 40,/— = 40 X 
¥ $257 == 73-028 feet per fecond, or 494 miles 
per hour nearly, the velocity of the wind as 
required. 
WMér. Hackman aifo anfwered Quflions II and Il. 

~NEW: MATHEMATICAL QUESTIONS. 
To be anfwered in No. V1. the Mag. for Fuly. 
Questiow AL. Sy Mr. i. F——r. 
To the Editor of the Monthly Magazine. 
SER, Da 
BSERVING it remarked in p. 133 of 
- your Second Number, that the fame 
umber of changes maybe made with a 
Telegraph as can be rung. upon a mum- 
ber of bells, equal to its number of boards, 
which is erroncous; I fend you the fol- 
lowing queftion for your next Magazine, 
andam, fir, your obedient fervant, 
i : i iS PS 
The Queftion.— Required a general theo- 
rem for afcertaining the number of fignals, 
or changes, which can be made by a tele- 
graph, confitting of any given nuinber of 
hoards, each hav.ng-one motion, according 
‘to the prefeat method ef confructing 
them (May 1798); and alfo the number 
ef different fignals that can be made, fo 
#hat any given portion ef the whole num- 
Original Anecdotes, Sc. Marat. 
[ May: 
ber of boards may be difp'ayed in each 
of them. 
casei XII-—By Mr. I. F——,r. 
Three obfervers, A, B, and C, in @ 
right line, take, at the fame inftant, on 2 
fignal, the altitude of a balloon: A finds 
it 1g degrees, B 18 degrees, and C 20 
degrees ; alfo B is 1000 yards from A, 
and C 1500 from B.—Quere, The per- 
pendicular height of the balloon. 
QvueEsTION XIII.—By Mr. T. Packman, 
In Waddington’s Land Surveyor’s 
Companion, p. 60, the following rule for 
reducing apparent levels to the curva- 
ture of the earth is given, viz. “ Multi- 
ply the fquare of the diftance, in chains 
and .parts (if any) by 124, and cut five 
places off from the produét, and you will” 
have the decimal parts of an inch to-be 
allowed for the curvature.’’—Quere, The 
inyeftigation of this rule, with a correét 
table for reducing apparent levels to the 
true. . . 
¥.% The Solutions to the Queftions above, muft 
be jent, vt the latel, in the Firff Week of Fuly. 
Errata. Ia the lofi, (No. Tb. ) Pa, 213, coh 
1,1. 24, fromthe bottom, the Ainamials x4-% and 
a—b thould be x+-2 and ¥—4, “Yb. col. 2, 
1. 4 ftom the bottom, for #e r. thar, Pa. 214, 
col. r l'2m% dele when Ib. col. 2,117 and 
18 from the bottom, r. different. Tn feveral 
places of thi:, and the two following pages, for 
B. Cygm, read 6, Cygni. Pa. 21s, cal. 1h 

4 
224 Read Hi ae Ib. 1. 33, forw = © read 
48 
ene Cd ee 
v=; Ib. cole, Ty Ags Cee read, 
uid 
Pa. 216, col. 1, 1.23, for 147,262,52'5 
ag" | 
read 147°262125. 

ANECDOTES AND REMAINS 
= EMINENT 
OLE 
PERSONS, 
[This article ts devoted to the reception of Biographical Anecdotes, Papers, Letters; ©c. and 
ue request the communications 
RNECDOTESOF PERSONSCONNECTED 
wiia tas FrRenen REVOLUTION. 
(Continued from our lofty 
Marat, 
TERMED by Dumourier, the Medu- 
+= f’s head of the Revolution, and 
whofe brutal withes, and barbarous avc- 
tions, have been eminently differviceable 
to the caufe of liberty, throughout Eu.. 
rope, was not, as is generally imagined, 
3 Frenchman. He was born at Neuicha- 
z 
Juch of our readers as can affift us in thefe objects. | 
tel the fovereignty of which, ever fince 
the diet of 1707, has appertained to the 
houfe of Brandenburg. He was there- 
fore a Prudiian. 
“It is well known, that he was a coward, 
who ‘ could fpeak daggers, but not ule 
them,” yet itis not of duch general no- _ 
toriety, that his hideous countenance was 
the cxaét counterpart of his heart. His 
body was placed in the French pantheon ; 
for under the monarchy of Robefpicrre, 
Marat wasa god! It has fiace been re- 
maved 
