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About The west shore. (Portland, Or.) 1875-1891 | View Entire Issue (Jan. 1, 1879)
January, 1879. THE WEST SHORE. a3 THE STRENGTH OF LOCOMOTIVE BOILERS. The following article is from the Railway Gazette of Deo. 20th: Of late yean, owing partly to the inorease in the size of locomotive boilers, and partly to the numerous explosions that have occured, the thickness of boiler plates has been materially increased. Twenty-five years ago there were few, if any, used thioker than Q-1G in. Now, for the larger sizes of locomo tives, plates are always jj and in some cases 7-16 in. thick. Double-riveted seams were sel dom found in the older boilers, whereas, now, it is the rule for horizontal seams, and in some cases for all others; and in the 'larger engines now in process of construction on the Louisville ft Nashville railroad the former are treble-riveted. The object of this increase in the thickness of the ma terial and in the method of fasteni ng it togeth er is to increase the strength of the structures; but a boiler is like a chain, the strength of which i8 only equal to that of the weakest link, and the misfortune has been that in attempting to increase in resisting capacitv of boilers, some of the links have been very much neglected. A house painter who should fall from a scaffolding by tho breaking of a rope would quite naturally get a stronger one if the survived the fall; but the strong rope would be of little servico unless it were securely fastened. Without knowing anv confirmatory facts it is safe to venture the opinion that many more accidents of persons falling from scaffolds are caused by insecure faiiteninyi than by insufficient strength in the members of the structure. The unfortunate man who undertook to lower his wife from the window of an upper story of the Southern hotel at the time it was burned was not mis taken about the strength of the nieces of bed ding whioh he tied together, but he had not the knowledge nor the skill to fasten them, and his knots slipped and his wife was killed. Tho weakness of boilers arises generally not from insufficient material, and perhaps not as often from inferior quality, as it does from the weakness of tho attachments of the various parts. Unless there is some reason for a contrary oninion. it mav lie assumed that riveted work will always be done badly. The ohief defects of such work are out of siiiht, and to a great extent undiscnvt-rahlo after it is finished. Mis matched and unfilled holes cannot be seen after the heads of tho rivets are formed, and there fora euoh work ii Insa aubiect to criticism and inspection, aud consequently there is little rivalry or pride of excellenoe in doing it among mechanics. Without the very olosest inspec tion it is alwavs possible for a workman to hide hia hlundnra and Ilia carelessness. Then, too, then- ia nn atrnnir annao of the necessity of good work of this kind. Thoro is generally a lack of what miffht lie called mechanical moral sense in this respect, and an engineer who should insist upon having tint-rate work would find it no easy task to have his orders executed. In the construction and attachment of tho braces, there is more carelessness ami ignorance displayed than in any other part oi ooiier cm struction. These are seldom carefully designed and am nearlv alwavs left to workmen to ar range. They are seldom delioient in the amount ol material o! which they are maue, uu often in the methods of attachment to the shell of the hnilor. In the attachment of steam domes there ui more disregard of the laws which govern the strength of locomotive boilers than anywhere el..- In nnler to mva aeoeas to the inside ol the boiler a hole from 24 to 31) in. in diameter must be cut into the shell. To make up for this there is the flange) whioh ia formed on the i base of the dome, and, in some cases, another flange which ia tamed upon the plate which forms the hell of the boiler. Both ol tnese m J bv th. riv.ta that their sectional area din.im.hl ik.a.l.v. What ia needed here, am what is used in Europe, is a heavy wrought-iron This can be riveted either to the boiler shell or to the dome, and in this way it will reinforce the strength of the boiler whioh has been dimin ished at this point. Broken stay-bolts we have always with ua Our present knowledge of the subjeet hat not thus far supplied a remedy for the evil. All we can do it to supply such means as will en able us to discover the breakage at soon as it occurs. Hollow stay-bolts plugged on one tide are the surest safeguard. It is a little singular that more effort has not been made to overcome the effects of uneuual expantion in locomotive boilers, If we reflect for a moment on what occurs when a Are is built in a locomotive boiler tilled with cold water, it will be seen that there must be enor mous strain exerted on it before the whole of it becomes heated. The tint effect of the tin is to heat the lire-box plates and tubes. These must expand baton the outside shell is even warmed. The expansion due to a rise ot tem perature from tay 70 to 400 it about 0.002 of the length of the tube, which if 10 feet long would therefon be inonaaed in length nearly a quarter of an inch. Thit pnttun mutt be exerted against the front and back tube-sheets and transferred to the shell of the boiler, The front tube-sheet cannot yield excepting to an almost inappreciable amount The outside shell will be stretched and the tunes compressed somewhat under the strain, but after making allowance for these effects it will be seen that the greater part of the strain, due to the elonga tion of the tulies. must lie exerted on the liack tube-sheet, and this in turn is transmitted to the aido-sheeU and stav-bolt of the tin-box. It ia nn wnndar tbev are broken. It ia remarkable that no one has devised any sad hn1 of c.nninensatina or uermittinii this ex pansion of the tubes without subjecting ths ither nana OI tne uouer to oiuowoa It .cms as if there were some wave defects in the principle! of constructing locomotive hoilen. Whether they can be remedied it is too early to .n,r hut it is certain that much of the work manship and the design ot tho details ooum no immonsely improved without any increase of knowledge on tho part of those who have charge of their construction, excepting that which every good mechanic should have, and whioh r 7 i -i . . tuu,L. can lie loumi ill SSSawnasBBara a ii I am RM.LULOID. This tubttanoe, though pre pared by Mr. Hyatt, an American, aa long ago as IWiV, lias omy iiwii " - - nHnliflil aeeollht. It ia urs pared by subject iiig ordinary paper to the action of a mis-tun nitric and suipnuno soma; wsuo.m .... trace of acid disappears; uryiug vno u,..Ue ....... i. r, i be name, and mitinu it with nam uhor; drying and repeatedly pressing this mix L . f..t .i.iilvinu heat, whim tho oollulolil .ppo'ars in the form of transparent, elastic rods or slal-a. As it IS hard and not easily broken at ordinary temperstuns, siiscepunie ,. .!,.), and capable ol iwing cuv mm .an-.,,. . H7Z .laatic. and. at tituli temiwra Willi I"" "l J ' .' ,1 1 tures malleable, plastic and even fusible. It hat liecome extensively used in the manufacture f tho runs of eyeglasses, cheap omaiiwnta, cigar aa- ,tc, andi when cu ored. at a moan. ""!:.:.. .L. Laws laauh and malachite. It ErJLZ3id ... ....king elastic bolt-, ..a ate . aud soma of its epplwntioue in dentistry M Patented as early at iU discovery. - Jfoatfsar dm ft thm. tt..,.r.. a. Oot oara:. Th. fishing smeeka Jung th. coast of Honda, report a mm iLh r poisonous water along the coast, that k .11. all th. Hah in its range I hey report .... mi fo 200 mil- through dd Hah. covenng ug lor aw nmeh wllh aj ,i vari.tU "mmed-ate'ly on th. shon the .star Ut and natural, hiU ls than a mil. off It appears of a red brick eotor. T, , MM of TititiM and snterteinmsi.t. at Washington hat begun. WHY THE SIERRA NEVADA IS LAIUiRR THAN THE COAST RANOK. A UllkND l.r THM YOKUTt. Stephen Powers, iu his "Indian Trilwa of California," relates occasional Iruenda of the t range people he visited. Many of these tra ditions are in themtelvot silly, child's tables, but viewed from the standpoint o( ethnology they possess peculiar interest. Tho tribe ot the Yokuts lived, or rather their romuauta still live. about the northern half of Tulare lake, reach ing aa far north at the beud to the eattward ut tho San Joaquin, and extending to the east and west at tar aa tho Sierras and the Coast lUngo respectively. Tho following legend belongs to this tribe. I'owors outillod it tho OHIIIIM lir I III Ml.rNTAINH, Once then wat a time when there waa noth ing in the world but water. About the place when Tulare lake ia now there wat a pole ttanding far up out nf the water, and on thit pole perched a hawk anil a crow. Flnt ont of them would tit on the unit awhile, than the other would knock him off and tit on it himself. Thus they tat on top of tba Pole eUve the watera for many ages. At length they wearied ot tho loneaonienoaa and they created tilt birds which prey on tlsh, such as tho kingfisher, eagle, polo an and oth.n. Among them wat a vary small duok, whioh dived down to the Ixittom ot the water, picked its Iwak full of mud, earns up, died, and lay Moating on tho water. I lie nawa and ths crow then loll to work and gathered inn., the duck's beak tho earth Inch It had brought up, and commenced making the moun tains, they ooinnionceii at tne piaos now known aa Ta-hi cha-pa laaaa, and toe hawk made the eaat range, while the orow mailt the watt one. Little by little, at they dropped In ths earth, these gnat mountains gnw athwart ths faoe ot tha waters, pushing uorth. It waa a work ot many ysars, but finally thty mat to gether tt Mount Sliseta, and Hour lalnra .-. ended, nut, IMiiuld, wnon ti.oy oniuparou tm.r mountains, it waa louud that tha oruw't waa a great deal the larger. Then the hawk aaid tu the .-row "How did this happen, you rascal? I warrant ynu bavo hem stealing soma ol tha en. lb from my bill, aud that is why your uiiiuii- . . .L(l. I - l' ... , I. tains are tne n.ukrsi. is wa taws, mm h- . . . , I i-i , i L. l crow lailgliod III IKS o.awa. I nn mm nw went and got some Indian tobaooo ami chewed it, ami it made him exuaadlngly wise. Ho h took hold ot the in, on, tain, and tinned thtm round in a oirole, putting his ranae in plaoa of the orow 'a; ami that is why the Alarm Nevada u larger than the Oasst Itsnge. This legeud is ol value, sayt I'owere, at atsow ing the aboriginal notions of geography. U oxplaiuing the story, tlie Indian drew In tha sand a long elllaM, representing quite aoou rately, tha ahaN ot the two ranpte , and ht ha, I never traveled away from King a river, Further, it may be sddad, this legend and all ot similar origin, are of value in nimetlng ths idsaa ot "city t'.lkt" with regard to ths Califor nia Indiana. Those who have atwn only tha H Ihggor" in hia debauched Indolence, at be hang, about some stage station, have no right to form an opinion, liasad upon their own etptri anos, ot thiata unlnrtuuaU people. They do not deserve the approbrium ettecnad to tha term " Ihgg'-' 1 '" 4"' i'lterasting trihaa, that have a history. They are tailing bsfora Ilia advanoe ol a people tar Utter than thmslves ; but not so much Utter, that tU uncivilised canm.t point to tU civiliswl aa tU haatonan of the luiltan's destruction "e shall all Ala soon," waile tha Yokate I. el. an in hia daoot tor tha dead. " Wa wen a gnat people onea, Wt art weak and little now. Ik sorrowful In our hearts. , let sorrow melt your hearts M your tears flow fast. We an ail ana people. Ws an all fnaoda. All our naarlt an one aaart" ring around the hole at mo oaae oi m -
