1840.] 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



419 



prepared ami partially put up in Trinity Church, for ventilating the parts 

 afi'ected with dry-rot. 



The growth of the parasitic plant, and the decay of the wood coming into 

 contact with it, seeming to he in a great degree contemporaneous. 1 am not 

 prepareil to say which is the cause, and wliicli is the efTect of the other ; but 

 X think that the growth of the plant takes precedence of the destruction of 

 the wood. 



I shall relate two or three facts which have come within my knowledge, 

 because they strengthen my conviction as to the most effectual means for the 

 prevention .and cure of the dry-rot. 



The usual manner of preparing the walls of a house for skirting-boards, and 

 fixing (hem, is likely to pruduce the dry-rot. as thus : — a coat of mortar 

 mixed with pounded glass tills up very closely the space behind the sk-rting- 

 boards, to prevent mice from having a run iHere. and a moulded cap of wood 

 is rabbeted and put up for receiving the plain board : on the door is sprigged 

 down a rib of wood, of about one inch squ re, for the whole side of a room, 

 without any intermission, and the skirting-board is then scribed and closely 

 fitted to the Moor, he. 



In a new house the walls and the plaister may not be perfectly dry. and 

 the same mischief which has been described in the pews of a church is likely 

 10 occur, and does so continually, in the decay of the skirting-boards, parti- 

 cularly on the ground floor ; but I think that it happens less frequently when 

 there are arched cellars below, which m ly carry off some of the moisture. A 

 little of the water in washing the floor, the skirting-board being in a dry 

 state, will find its uay behind it, and increase its liability to decay, by im- 

 pounding a little more moisture. 



I Iiave observed this to take place to some extent in fifteen or twenty years 

 after a house has been built, but not perceived till the damage w ,s consider- 

 able, because the paint will conceal it. In replacing the skirting-board in- 

 stead of a continuous rib of A\-ood sprigged on the floor, I have taken jiieces 

 of a foot or foot and half in length, leaving a vacant space of two or three 

 inches between them, and not fitfing the skirting-boards very closely to the 

 floor, so that a small circulation of air may be preserved ; and no decay has 

 occurred in a similar period, at least I can answer for a term of thir'y-five 

 years from the erection of the buibiing. 



When a new mansion house is to be built, it often happens that a certain 

 quantity of sound limber I'rom an old house is to be made use of, in the shape 

 of beams, joists, Sec. and the old beams and joists are apt to be immediately 

 applied to the ground floor, which is a great mistake. An instance of this 

 having occurred within my knowledge, I must give a minute account of facts 

 and consequences in order to bring them to bear on the points which are un- 

 der consideration. 



The front of the house faces the west, and consists of two principal rooms 

 extending length-ways to the right and left of an entrance room, the floors 

 being three steps above the ground ; and 1 am pretty sure that the joists, if 

 not the beams also, were of uld timber: the boarded floors were of the best 

 Baltic oak, prepared and finished in the most careful manner. Beneath these 

 front rooms there are no cellars, but arched cellars extend under all the back 

 rooms, which appe,ar to have prevented the evil that I am about to describe 

 as havi: g occurred in the floors of the two principal rooms. 



In the course of twenty or t^\■enty-five years from the building of thehouse, 

 the deal skirting-boards on the outwai'd walls were found to have decayed, 

 particularly on the west, and the floor sunk nearly an inch in some places 

 from the skirting-boards. It was evident that the joists had failed at their 

 insertion into the outward walls. The floor was then taken up for an open- 

 ini, suflicient to admit a man with alighted candle, who crawled on his hands 

 and knees under the floor, to ascertain the extent of the mischief: the para- 

 sitic pi :nt or the dry-rot had got so great a footing, that it became'a question 

 whether the whole of the tw o floors ought not to have been taken up ; but it 

 was at length resolved to try the eflect of a less expensive operation, w hich 

 at tile present time, after a lapse of ten or fifteen yeirs, seems to have an- 

 swered perfectly well. Several new oak joists were j^laced crossways beneath 

 those which had partially failed, and as nearly as conveniently might be to 

 the decayed ends of those joists which had wholly or in part lost their holds 

 upon the outward walls, propping the new joists with bricks, slates, and 

 stones ; and the skirting-boards were then replaced in the manner before 

 described. 



But the thing on which the greatest reliance is to be placed was the pre- 

 paration to be made fi r the circulation cjf air beneath the floors: plates of 

 iron were cast three inches square, perforated w ith many holes of a quarter 

 of an inch diameter, four of these plates were applied to each of the two 

 rooms, two distantly from each other, at the two outward sides of the walls, 

 below the floors, and two on either side of the fire-places in the floors, wdiereby 

 a continual circulation of air w'as established, and his ever since been kept 

 up : and I conceive that the progress of the dry-rot is stopt, while the supply 

 of air required for the fires is materially assisted. 



The disagreeable mouldy smell of dampness accompanying the dry-rot was 

 evident enough as soon as the floor was opened, and continued to be less and 

 less perceptible for months, or perhaps years, thr, ugh the small g:-ates ; but 

 those near the fire-places were covered occasionally: the grates had better 

 have been made of brass one-;hii\l or one-fourth of an inch thick. I shall 

 bring forward only one more instance, to prove that confined moisture is the 

 cause of the dry-rot, and I must again be very minute, that I may be the bet- 

 ter able to support my suggestions when I attempt to apply them to general 

 purposes. 



About the year 1820, or a little later, there was occasion to build a new 

 sitting-room tit a farm-house, and the site fixed upon was over a cellar, then 

 roofed as a shed or lean-to : the new floor was approached by four steps out 

 of the kitchen, the walls were built of rubble-stone eighteen inches thick, the 

 size of the room is 14ft. y in. by 11 ft. 6 in. — the floor over a slope, and from 

 four to two feet above the grtamd, w hile a grate of seven inches square venti- 

 lates the cellar from the north. 



The object of this is to show in how short a time the new floor was totally 

 destroyed by the dry-rot, without in any way accounting for it, but from the 

 floor itself. The joists were cut out of sound poplar, probably the upper or 



inferior parts of trees, and between the joists were nailed ribs of wood to sup- 

 port short pieces of boards for grouting in the usual manner of counter-ceil- 

 ing, the floor was neatly laid with inch poplar boards well seasoned, planed, 

 and of the best quality. 



In the course of a few months, I believe, the floor joists, boards, S:c. were 

 entirely decayed, excepting a few feet near to the door out of the kitchen, 

 which were only partially so. Although, 1 believe, that the decay was very 

 rapid, I can only assert from recollection of some other particular occur- 

 rences, that in the course of three years the room was built, the one floor 

 laid, that floor decayed, and a new floor put up, which is perfectly sound at 

 the present lime, after a lapse of more than 17 years 



The present floor is mule of oak teams and joists, and very good poplar 

 boards, without any ceiling or laths and plaister under them. 



The » ay I w oiild account for this extraordinary instance of dry-rot is, that 

 the walls were damp when the first-mentioned floor was laid, and that the 

 counter-ceiling was very damp, that the boards were dry and closely fitted, 

 that a fire h as rarely (if ever) used in this room, and that the progress of the 

 dry-rot was extremely swift, as it would be in any case under similar circum- 

 stances of confined muisture. 



I may mention chamljer floors of poplar boards at the present time, over a 

 considerable extent of kitchen and other ofiices, which have been laid down 

 for thirty-five years, and are as sound now as tliey ever were : although I 

 have seen poplar boards used as window shelves in inferior apartments, and 

 in some other ways, which have gone into complete decay, grub-eaten or 

 otherwise, in the course of a few years. 



The reader who may have wailed through tho details of facts, which I have 

 thought necessarv for my purpose, may wish to have the conclusions drawn 

 from tliem recapitulated in a few short sentences, as' thus :— That wherever 

 joiner's work is to be fitted to newly-built walls, there should be means 

 taken for the circtilation of a little air. That the beam, and joists used for 

 the ground floor of a house should be of British oak, larch, or best foreign 

 deal. That the ends of beams or joists inserted into the outward walls of a 

 new house, on the ground floor, should be eased with sheet lead, zinc, or 

 cast iron, all impervious to moisture, but not too tightly fitted, for fear of 

 the sap's producing confined moisture ; or they might be secured at their 

 ends with cases made on purpose of fire-brick clay, or other clay impervious 

 to moisture. I have used cast-iron sockets and fire-brick cases very satis- 

 fectorily. That the wooden ribs upon whicli the lower edges of the skirting 

 boards are to be nailed should not be in continued lengths, without some 

 intermission. That wherever floors are laid with stone bricks, or slate flags, 

 the skirtings should be made of slate-flags from three-quarters of an inch to 

 one inch in thickness, with one sawed edge. That in servants' halls and 

 other oHices. where it may be desirable for the skirting or dado to extend to 

 the height of three feet or more, slate-flags of three-quarters of an inch cr- 

 one inch thick, might very properly be preferred to wood, but capped with a 

 grooved ledge of wood ; these slate-flags being worth only about 9cl. the 

 square yard. 



Many of the particulars respecting the rooms which have been affected 

 with dry-rot may, as I have observed before, appear trivial, or even ludi- 

 crous ; but when it is recollected that we have been alluding to facts that 

 oceurre 1 fifteen or twenty years ago, and which engaged attention only for 

 the moment, I wish to state what is still to be seen ; and more particularly 

 to sh"W, that there was nothing in the position nor dimensions of the room 

 last-mentioned, neither door, window, chimney, nor any other circumstance, 

 whereby such an eflect of dry-rot could have been produced or promoted, 

 excepting only by the confined moisture, and to which al ine the dry-rot is to 

 be attributed. 



A simnle remedy for any grievance is sometimes unpopular, aiid you may 

 be advised to poison unwelcome vegetation as you would rats, without con- 

 s dering that poison, like gun-powder or steam, is not a thing to be played 

 with.* Is it not more reasonable to trace a mischief, if possible, to its cause, 

 and by removing or counteracting the cause, endeavour to prevent or arrest 

 the progress of the eflect ? .Suppose that a ship may be liable to dry-rot, 

 from confined moisture and the sap ( juicej of unseasoned tiinber,t the natural 

 remedy would be to give a change and circulation to the stagnant atmosphere 

 by ventilation : I see no reason why dry-rot in a ship might not be prevented 

 or arrested by a suflicient number of small grates, wliich have been used so 

 successfully about ilie floors of the two rooms as above described.— «ato/jia« 

 Journal. 



ON THE ECONOMY OF RAISING WATER FROM COAL MINES ON 

 THE CORNISH PRINCIPLE. 



At the annual meeting of the members of the Manchester Geological Society, 

 held at their rooms, on Thursday, the 29th October, Mr. Fairbairn read a 

 communication •■ On the Ecenomy of raising Water from Coal Mines on the 

 Cornish Principle." In introducing his piper to the meeting, Mr. tairbairn, 

 after explaining the sections of the engine and pumps made by him lor some 

 Belgian coal mines, said, that the improvements introduced ot late years into 

 the Cornish engines, w ere of so important a nature as to be high.y worthy 

 the attention of the miners of this district. They had not. till very lately, 

 the slightest conception of the great saving effected by the performance of 



'■■ Corrosive sublimate is the only known specific, mineral or vegetable, for 

 preventing the growth of the dry-rot fungi, and which, I believe, has formed 

 the basis of Mr. Kyan's patent. . 



T Oak would require less seasoning, and be much fitter tor use, it it were 

 cut down in winter instead of in spring. I recollect, some fifteen or twenty 

 years ago. observing a sound oak plank in the gable end of a house which 

 was under repair: some of the sap (alburnum) and bark was still on the oak, 

 and very slighily grub-eaten, although it might have been in the building 

 an hundred years, perhaps, or more, on the inside of an outward wall, nogged 

 with bricks, and never had been covered with plaister nor colour of any sort. 



3 L 2 



