342 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



[Octo'bkr, 



I have mvself s''cn tliousanils of trees Iviug in the woods of Amcriea, in the 

 state denominated " logged," ^tl.at is cnt into Ici.gtlis for the mills) which, 

 were rapidly hastening to decav, and in almost all these cases it was owing 

 to their having heen cut in the winter, as there all the logs are left after being 

 cut, till they are needed for the mill, and mauy are so left fur months, nor is 

 it uncommon to sec timber under the saw, of which at least one-third is at 

 the lime in a state of absolute decay. 



Your's, very respectfully, 



J. IIOI.DEN. 



36, Jll Saiuls Place, Ormund Slrcet, Manchester, 



August 22, 1840. 

 " Mr. Rainey, of Middletown, Conn., a bbip-bnilder of considerable ex- 

 perience, having become convinced that the sap was the cause of the decay 

 of wood, instituted a scries of experiments to ascertain its place iu ditfcrent 

 seasons of the year, and found that in the winter, the heart wood contained 

 raucli more than the sap wood, while in the summer it seemed concentrated 

 in the alburnum or outside layers of wood. It has been generally supposed 

 that the sap of the tree was principally in the roots during tlie winter, and 

 acting on this supposition, Mr. Eaineyhad preferred for ship building, timber 

 cut in the winter; some cases, however, iu which timber cnt in the summer 

 was used with that cut in the winter, and remained sound while the latter 

 decayed, induced an investigation as to the cause, and resulted as stated. Mr. 

 R. now uses timber cut as far from December as possible, and finds much less 

 cause for complaint than formerly. The following was one of the experi- 

 ments that led Mr. R. to doubt the propriety of cutting timber in winter :— 



" ■ Having cut a small oak staddle, on or about the 20th of June, I placed 

 eeveral pieces of it in the fire place, and put a fire under them ; after a little 

 while there appeared at the end of the sticks a wet circle describing the exact 

 thickness of the albiu-num, or sap wood, and when they became considerably 

 heated, the steam rushed with violence from the tubes of the sap wood, while 

 there was but a small appearance of vapour from the heart wood. About the 

 same day of December, of the same year, I had another small oak cut, and 

 went through with the same process of heating several pieces of the wood ; 

 and wiien they began to be heated, the whole surface of the heart wood, ex- 

 cept a small circle enclosing the pith, was wet, but the alburmim was dry, 

 and when they were fairly heated through, the steam rushed with violence 

 from tlie heart wood, though the whole epiantity that escaped, was not so 

 large as iu the former case. The results of these experiments accord with a 

 well known fact in regard to the sugar maple, namely, that no sap can be ob- 

 tained from the tubes of the alburnum of the tree, and therefore they are ob- 

 liged to bore a hole for the tube through the alburnum, into the heai't wood 

 before it w ill run.' 



'• Mr. Kainey's inference as to the position of the sap during the severe 

 weather of winter, is probably correct, as we have observed many appearances 

 that ^vould go to confirm it ; but, that at the time of making sugar, the sap 

 is found in the heart wood of the maple, is decidedly incorrect, as every per- 

 son acquainted with the manufaclr.re well knows. In many cases in tapping 

 the trees, the heart wood is not touched at all, and it is deemed desirable to 

 avoid it when practicable.— The sap of the maple will not, however, flow 

 until the temperature of tlie earth and air has been raised by the sun of 

 spring, and the circulation, which is partially or totally suspended iu the al- 

 burnum during the severe frosts, is restored.— The relative position of the 

 sap is consequently changed from what it was a few weeks previous, having 

 passed from the centre to the surface through the lateral pores, or what is 

 called the silver grain, as well as commeuced its flow upwards to the expand- 

 ing leaves and branches. 



" Farmers find the cutting of timber for posts and rails an important item 

 in their profit or loss account ; and if Mr. Rainey's experiments as to the 

 duration of timber can be fuliy relied upon, or substantiated by further ex- 

 perience, a very great )>oint in domestic farming economy would be gained. 

 We think the early settlers of Western New York could throw much light on 

 this subiect, by ascertaining the relative duration of their rail fences made 

 from tiniber cut in the winter, or midsummer, as most farms must have had 

 Bpechuens of both kinds ; and any notices of this nature, furnished us, shall 

 be inserted with pleasure." 



TIDE GAUGE. 



c,R J5y attention was directed by a friend, who is a Civil Engineer, to a 



j)aragr.iiih in " The Civil Engineer and .A.rchitect's Journal," for May 1838, 

 under the head of " Proceedings of Scientific Societies," Royal Society, giving 

 a description of a new Tide G"auge, constructed by T. G. Bunt, and erected 

 on the eastern bank of the river .\von, in front of the Hotwell House,. Bristol, 

 in 18.37. At this I was astonished, as 1 was on a visit at Mr. Mitchell's, at 

 Sheerness Dock-yard, three or four years since, when Mr. T. G. Bunt was 

 carrying on a seljf-cstahUshed con-espondence with Mr. Mitchell, n-ho was a 

 strmtijer to fimi, and Mr. Mitchell, to my knowledge, actually sent him a 

 drawing of his tide gauge with a description, wliich so sinyularly and so 

 niicli/ ayrees with that given by Mr. Bunt of his neiv lido ijamje ; and Mr. M. 

 showed me at the time, some of the letters that he had received from Mr. 

 Kiint, which had they come to me from a stranger as they did Mr. Mitchell, 

 I should have thought it great impudence. I have since shown this para- 

 graph to Mr. Mitchell, who, like the immortal Watt, with " dirty" Prony, 

 was too inoft'ensive a man to attack the person when the injustice done was 



mentioned to him. I have since this again asked Mr. Mitchell if he had 

 known Mr. Bunt before.' He replied, no; nor have I ever seen him. I 

 asked .Mr. M. why he ever answered the first letter? He said (and should 

 this meet his Mr. M.'s eye, 1 hope he will forgive me publishing private con- 

 versation), " why, really I thought the person Mr. Bunt, might have afamily 

 like myself, and might be it riving to gain something by working out his owu 

 ideas, at seeing mine in its complete state, but I had no idea of such as you 

 have shown me." 



ilr. M. then again showed me his " tide gauge," which as aforesaid, was 

 erected in all her Majesty's Dock-yards, and has answered admirably for 

 years ; he also showed nie that of Mr. Lloyds, which is quite different. 



A description of Mr. Mitchell's tide gauge may be seen in the " Nautical 

 Magazine," for one of the months In the year, I think, of 1835, and wliich 

 was inserted by a frienil of Mr. M.'s, at that frhnd's reri/ kind request. 



Now these facts, for the good of the community at large, especially the 

 various scientific gentlemen that read your Journal, whose protection is of 

 importance, I lay at your disposal, and as it is the duty of every person to 

 crush " plagiarism," I have forwarded this, which I would thank you to give 

 insertion in your valuable scientific and interesting Journal, as a "beacon" 

 to warn persons from being unexpectedly similar passive objects. 

 I am. Sir, your obedient servant, 



James Inglis. 



London, Sept. 2, 1840. 



P.S. — Since writing the foregoing, I have seen Mr. Mitchell's son who 

 made the drawings and WTOte the description that was sent to Mr. Bunt of 

 Mr. Mitchell's tide gauge, who says that the correspondence could doubtless 

 be produced. 



[We have omitted the first part of Mr. luglis's communication, as it only 

 relates to the invention of a tide gauge which has failed, there is no charge 

 of plagiarism against the party. — Editor.] 



YSTALYl-ERA ANTHRACITE IRON. 

 Mr. Evans, of Manchester, has given a report upon the strcni/ih of the 

 Y'stalyfcra .\nthracite Pig Iron, of the several qnahties, Nos. 1, 2, and 3, with 

 a view to ascertain its properties, particularly in relation to other irons, being 

 the result of about 28() experiments upon rectangular tiansverse liars. The 

 experiments were made liy breaking the bars between supports of their dis- 

 tances ; namely, of 4 ft. iu. and 2 ft. 3 in. apart. 



The trials were confined to the transverse strength of 1-inch rectangular 

 bars, with their several values, as under : — 



1st. Specificgravity. — 2nd. Modulus of elasticity. — 3rd. Transverse strength 

 of 1-inch rectangular bars, 4 ft. 6 in. apart. — 4th. Transverse strength of 

 1-inch rectangular bars, 2 ft. 3 in. apart.* — 5th. Ultimate deflections. — 6th. 

 Power to resist impact, of v.hich the tables f are divided into, and contain 

 bars broken from 



72 spec-imens of No. 1, 

 65 ditto of No. 2. • 



.61 ditto of No. 3, 



all cast horizontally in stand, melted by coke from the cupola in the usual 

 way ; — 



44 specimens of bars melted as above, of equal mixtures of Nos. 1 , 2, & 3 ; — 

 24 specimens ditto, of the same melting and mixture, but afterwards planed 

 down to a perfect 1-inch square gauge; and — 



16 specimens ditto, of the same mixture, but melted in the crucible. 

 The area of breaking section is calculated as the square of the depth, info 

 the breadth, and inversely as the length ; an example of which is subjoined, 

 for the bars requiring reduction to I'OO inch square from excess of area at 

 the fracture or otherwise : thus. No. 12 measured, depth 1-002, breadth 1-005, 

 which, reduced, stands 499 5 lb. in the table, under the head of 4 ft. 6 in. 

 bars. 



Rule. — To find from the above table the breaking weight in rectangular 

 bars, calling-4 and d the breadth and depth in inches, and I the distance be- 

 tween the supports in feet, and putting 4-5 for 4 ft. 6 in., we have 



= breaking weights iu lbs. — The value of S being taken from the above 

 tables. 



For example: What weight would be necessary to break the bar. No. 21, 

 in No. 1 table, 2 inches broad, 3 inches deep, and 6 feet between the sup- 

 ports ? According to the rule given above, we have i = 2 inches, <?= 3 inches, 



i-byihd-S 4-5x2x3-x484 

 /=6fcct, 5=484 from the table. Then- 



0534 Ib.J 



/ 



'■' The 2 ft. 3 in. bars are reduced to 4 ft. 6 in., as being a fair method of 

 obtaining a more correclmean; a separate column in the tabulated lorm being 



set apart for them. , , », i^ 



T 'hie report contains six tables of experiments made by Mr. Iwans, «e 

 have given the table only containing the mean result of all the experiments. 



~; The modulus of elasticiiy is taken from the deflection caused by 112 lb. 

 on' the 4 It. 6 in. bars. , „ . , i ,,,-,, i ■ i 



Elasticity calculated from the deflection caused by 112 lb. on inch square 



