The New Stccombaat Law. 141 V

This equation will serve to find c, when the velocity of the circumfe-
rence of the wheel 3/ is known. Our equations (ll) and (V) give the
velocity V of the point c itself; in this case to find c, we must consider
that the velocity of 1:, namely : V is to that of the circtnnference y as c to

____f‘__V,d _’l7 ____j’____, B .. j.

a, ory .— 6 , an as n._—;-, n _. c a V ._ L m. y substituting this
value ofn in our equation for c, we shall find c by solving a quadratic. in
all the equations the diameter of the wheel, 1), l1’l'l.~3t be ttrken as '2 c, not
the actual diameter from out to out ; it will generally be sufliciently near
to measure from the middle of the paddles.

lt is evident from equation (Vlll) thutifa boat working at full pressure

‘in the cylinder, were to take three similar boats in tow. the velocity would

be reduced to one-half, while from equation (Vll), if the power of the
engine remained constant, it would take seven other boats to reduce the
"velocity to one-half; the reason of this difference is, that in the first case
a great part of the steam would escape, not being able to enter the eylin.
der, and from this it follows that a tow boat should never work at full
pressure, or the steam will be wasted when most needed. '

All our measures are given in feet, and the velocities in feet per second,
also the pressures are expressed in pounds per square foot, and the water
evaporated in cubic feet per second. I

1 have found that these equations answer, by makingf-5 1943; 72 =.
‘I08, for a good model; m : 2; /c : -002; andz = 43-. ‘

- E. C. BnLL1.\'GEn.

(From the Journal ol'Commerce.)

The New Steam Boat Law.

We will go as far as any one in support of any pra.cticabIe measure for
the greater security of life on board ofsteamboats; while on the other
hand it is evident, that any measure which only seems to promote that
result, but does not in fact do so, is an injury both to steam-boat proprietbrs
and the public. It is an injury to the former, inasmuch as it causes
them trouble and expense; and to the latter, inasmuch as it begets, if
triisted in, a misplaced confidence, which endangers life instead of‘
protecting it.

In this light we regard the new Steam Boat law ; at least that portion
of it on which most people not conversant with the structure
of steam-boats and machinery, will be apt to place their chief reliance.
The provisions which require iron rods or chains instead oftiller ropes,-~
a suction hose and engine,—-a suitable number ofsniall bonts,—-—and signal
lights at night,-—-are reasonable and practicable.”“ _So would have been a
provision requiring each boat to be supplied with a number of life-.
preservers, equal to the usual number of passengers. But these are only
incidentals. The prominent features of the bill are, 1. That which
provides for a system of inspection; and 2. That which makes the
proprietor of a steamboat responsible for all injuries which may occur to
persons or property on board of the same, by reason ofexplosions or other

*Yet the phrnseology indicates that the framers of the law were not much
conversant with the subject upon which they were legislating. Do they mean that
iron rods or clmins shall extend to and pass around the wheel? That would be
a.ttende.d with great difficulty, to say the least. And as__to signal lights, there are
much better and more eflficient regulations now in force in this part of the country.
under State laws, than are required by the Act of Congress.