327

Awn TSTTTLDING CONTRIVANCES.

'“'•I AND BUILDING 5 & 6.

North Gallery, alp ^ _ _-___-—— -

-—-—-—-'-~ 1 weather ■when accidents are most likely to

f a PParat US for a fixed light being prodded, J0“P« sed ta^^P^able; so that ityderangement

: f a central cylinder and two zones of catadioptuc ring , alteration winch reduces the 1 y

onning a cupola and lower part, a certain numbei “ is i re atly to be appreciated,enses are arranged at equal distances from each , Fig. 2.

placed upon an exterior moveable frame, making L? ,,

Solution around the apparatus in a given period.

mnses, composed of vertical prisms, are of the same am A_ i\

tade as the cylinder, and the radius of tlieir curves is 111opposite directions to those of the cylinder, m such amanner that at their passing they converge into a parallel

Jencil of light; all the divergent rays, emitted honzou- ,

tally from the cvlinder, producing a brilliant effect, 1hat obtained ■ wes. at the revolving

■ghthouses.

lanner tnat at men ° „„ nt ra’

'encil of light; all the diverg,01 1 - bl . ilvi ant eaw—

ally from the cylinder, P r “ “flenses, at the revo-Hat obtained by tlie use ox a

licrV>+V»rmc/Ao •»

^obtained by tlie use w ...-

Dnthouses.

1 th 16 v lSt * m P r °vement exhibited has a special referenceIQ e “ght, and produces a considerable increase in itss ai er ’ whilst the simplicity of the optical arrangementsJens' 0 lauded. It consists, firstly, in completely dis-j ec ln .8 "with the moveable central cylindrical lenses.c °m d 1 '' re Pt aces these by a single revolving cylinder,light ■h™ r annular lenses, and four lenses of a fixed

■vary' lu ' ro( luced between them; but the number of eachduee i"^ acc0l 'ding to the succession of flashes to be pro-

■j, >n the period of revolution.p]j ea( ? s ccom] improvement, of which already some ap-Port a 10US " la ' have been made serve to show the invr eyo j tl . ce > consists in a new method of arranging thementl ln ® P art ’ ex perience having shown that the arrange-su(h„. at P resen t in use are very faulty. A short time ison I° r the action of the friction rollers, revolvingc uttill ° Parallel planes, to produce, by a succession oflarity® S J a sufficiently deep groove to destroy the regu-'hconv» ■ t ^ le r °l atol T movement. To obviate this greathited eilleuce i the friction rollers are so placed andv erg ; u on a n iron axis, with regulating screws and tra-'■tiem?.- et V een two bevelled surfaces, that when anau °ther 10n * S mat ' e in one P' ace , they can be adjusted to

The th ait °-*' t * le P^ ates which is not so worn,ctease t , improvement produces the result of an in-a PParat P ower of the flashes in revolving lighthouse% ^ us > '° double what has been obtained hitherto.*°hgati 0 11S ' enses °f vertical prisms, placed in the pro-l-ays " s of the central annular lenses, the divergentinto a st ergiu S ft' om the catadioptric zone are broughtis olm; ra lsht line, and a coincidence of the three flashes

with ***** the prisms, lenses, and zones are mountedP°!ished antl simplicity, accurately ground and

s Pcctiv e t0 .'! le C01T ect curves, according to their re-system so as to oroperly develop this beautiful

Posed is e Tresuel.” The glass of which they are com-that grp , " le clearest crystal colour, and free from°f the lij? *‘ ue which so materially reduces the power°f thi s ]£* V an< ^ I s considered objectionable for apparatus''Shted c ’• '*'* le lara P> by which the apparatus is to be"delis, att nS i 1StS a concentric burner with four circular

being ’ f 0 ac hed to a lamp of simple construction, the oilonly, ^d up to the burner by atmospheric pressure1° become de l * ,er ^ are no delicate pumps or machinery

Ve Sseh r °(I?? luutern and revolving apparatus for a light- ■CQn sist s P leBente d in fig. 2. The principal improvement'he deck ! cons ' r ucting the machinery to work beneath'■cal rod ’ ' ls ' e iof in the lantern as formerly. A ver-1? ast > With fit!" 8 in metal bearings, is attached to the'he rod, at la I g I“ gun-metal pinion fixed to the top of :la nterti’ wi. 6 . S^t to which it is necessary to hoist the‘■Oct witfi th^ 111 - a - tra ' n °f cog-wheels are placed to con-;? ll »ed therpf? P'nion, and communicate the motion ob-. le lanip s an 0 ® H ' 0 'h e traversing apparatus that support:

reflectors. The advantages of this arrange—""ich liirhtei

BSW

•ortT *“ —

t heZ7 n “ ala'if. metal hearings, is attacneu „d ' af tb« hf;„f““: n ‘ e , t . al , T ,n . 10 " fi xcd to the top of■ > which it is necessary to hoist the- 1 to con _

t comm U iavi..v __ ; ,

.ectors ^® rsin ,& apparatus tliat supports .. J -,

the ro a e > that the Unto ^ a<lvan,a g es of this arrange- “ ,ul iet0 “ r “ e ‘ ,u 8 .

I. 1 '? mast!f 0f , ^hc Vessel Tan^f w ma fi e much lighter, There is also an advantage derived from the novel

J- n, S niorf a< * ' s greatly diniini«J,<m S ° ? re , at 3 wei g !lt at construction of the lamps and gimhal work which, by a

"h great,,. u "der control -nirl L <* * ie mac h>uery movement exactly coinciding with the motion of the

r "o- u ] ai .; tv better protected, works vessel, causes a perfect level to be always maintained,

* SI . on ‘ and insures tlie proper flow of oil to the burners, how-

~»*v»onf S nia y ever j rre g u j ar tj ul t motion iu ‘ This improvement

■* so recent an intnx ’

-a i u . ,

I tnast-^p^i • he ves sel causeu „„ 0 .

, 'fibg ntore ^ S p eatly diminished, and the machinery u^ —v >th g re Ruder control and better protected, works vessel, causes apem—-A*> idea of '\S u l a rity and precision. and insures the propel' now ° . qn,; g hnprovemem

pined hy *' le utility of these improvements maybe ever irregular that motion «d■ • former but

■ght-vessel'^ ect j u 8' that, the situations in which tlie is not of so recent an m roduetnn £ *hi. IJ ^ ^ '^cls are p !acwi , are at flU time8 dmicult pf accegS) wljeu it W as first invented bj one of the cxliU.itms pio