On The Testing And Strength Of Railway Materials, &C.

" The supply of Riga timber has latel y been limited , but the foregoing remarks as to Memel and Dantzic may be taken as equally applying to Riga . " Sometimes a parcel described as ' Thirds' comes over equal to good seconds ; and , on the contrary , many parcels of seconds ought properly to be described as thirds . Our London system is to buy the timber in the water at the docks , Avhere it is rafted in floats , as it is discharged from the vessels . A float of timber averages 18 loads of

50 x 50 cubic feet ; it is rafted sometimes single and sometimes double , and by walking on to the rafts a good judge sees at a glance the general quality of the cargo ; and in special cases , if worth the trouble , may go through and select his timber stick by stick , on an understanding Avith his merchant to that effect ; the only expense thereby incurred being the cost of re-raffcing—in taking the rafts to pieces ancl fastening them

up again . " The disadvantage of our London system is that , as a rule , timber is ahvays used Avet , not only containing its native sap , but also the absorption consequent upon being perhaps some months in the Avater ; hence , Avhen care is not taken , arise those terrible shrinkages that sometimes occur . I recollect the case of a large house Avhere the Avhole of the interior divisions were carried out by a series of heavy quarter partitions ( without any brick internal party Avails ) resting upon each other to 40 feet hih . No

up g pre cautions Avere taken against shrinkage , and the consequence Avas that Avithin a few months after erection the Avhole of the floors , especially the upper ones , were out of level . The roof gutters Avould not take off the Avater ; every plaster cornice in the house Avas cracked , and the expense of reinstatement was very serious , tho sole cause being the shrinking of the timber . In heavy roofing too I have seen serious results from the same cause .

" It is vain to attempt to buy seasoned whole timber—there is not such a thing in the market . The only cure is that in the designing of the building the arrangements should be such that at no point shall the shrinkage of timber have the effect of injuring the stability of the Avork . In the present day , Avith our facilities in the use of iron , this is easily accomplished . A good deal of Swedish timber has recently been imported and extensively used , though never mentioned in the specification or supposed to be allowed .

It has much improved in quality of late years , and there is no real practical objection to its use except iu name , as for most purposes , if of good quality , it is just as good as Memel , Riga , or Dantzic . It should not be used in large scantlings Avhere weights are to be carried , as , though tougher than the other qualities , it is not so strong ; but for smaller scantlings it is perfectly adapted . The absence of turpentine renders Swedish timber less durable than ' Memel' or ' Dantzic' for damp situations , such as ground

joists or tide work , Avhere the timber is alternately wet and dry . "When seen in the stick , before cutting , a certain difference in the method of preparing it for the market enables the practised eye to detect it at a glance ; but when well selected ancl the slabs taken off , in many instances , Avhen mixed Avith Memel in scantling , no man in London can say which is Avhich . This very remark was made to me by an architect of forty years' standing , who had raised himself from the bench by his oAvn exertion and self-education , and a lengthened practice confirms me in this vieAv .

" Of course there are certain characteristics of the timber that are distinctive—there are certain pieces of Swede that no man Avould pass for Memel , and certain pieces of Memel that could not be mistaken for SAvede ; but the per-centage of both qualities to Avhich this last remark applies are certainly not more than 10 to 15 . As Swede is generally about 30 per cent , cheaper than the other descriptions , I need not say that its use is far more extensive than is generally knoAvn . " The folloAving ports are the best : SundsAvaldSoderhamSwartwickand Lluyane .

, , , These generally produce a full sized timber , and the Lluysne has this advantage , that it generally takes a reddish tinge when saAvn ; and Avhen that is the case is not to be distinguished from Memel , to Avhich it is not inferior in point of fact . From the other ports the Avood runs smaller , and is therefore wasteful iu conversion . "As a general rule SAvede timber is apt to run taper , and in estimating an extra