I.F.ARK IX SCOTLA 



I. r \THKR MANTKACITKi:. 



I 



1 of a Isaw for a yar. In a deed of release, was good evi 

 , __jfr |a***> against a relasanr and all claiming under him (but 

 at stranger*), without proving that there wa* such a deed, and 

 was lost or Jssttoysd. Not only estate* in possession, but 

 ia remainder and reversion were conveyed by lease and release. 

 4 ia remainder and reversion expectant on estates for lives might 

 b* ooaraved by lease and release; aa also incorporeal hereditament., 

 such as advowsona, tithes, renU, Ac., for they are expressly named in 

 the ftututr of Usas, or comprised under the general word heredita- 

 Mdta. (4Cni. /**. HI. "Li 



Ln-r awl release wa* one of those which were technically called 

 tnrfr-4 conveyances, in contradistinction to those which are termed 



. and release did not divest any estate, or 



or forfeiture. Thu* Littleton says : " By 



(ore* of a nluio nothing ahall pan* but the right which he may law- 

 fully and rightfully release, without hurt or damage to other persons, 

 who *h*M have right therein, after hi* decease." And in a subsequent 

 saglion b* ssys : * If tenant in-tail let* the land to another for term 

 of year*, by force whereof the lessee hath possession, and the tenant- 

 in tail reins* all hi* right in the same land, to hold to the lessee and 

 hi* heir* fur ever, thi i* no discontinuance : but after the decease of 

 the tetunt-in-uil. hi* issue may enter ; for by such release nothing 

 passeth but for time of the life of the tenant- in-tail." 



The Act 4 ft 6 Viet c. 21, made the lease for a year unnecessary, 

 and instead thereof it wa* only required that the act should be referred 

 to in the releasing clause, which thereupon took the same effect as if 

 the lease had been actually made. Subsequently the Act 8 & 9 Viet. 

 e. 1 10, by enacting that corporeal tenements should be deemed to lie in 

 grant as well a* in livery took away all necessity for the legal device of 

 a rnlnasr ; and the simple word grant now supplies the place, of the old 

 cumbrous msrhineiy. 



LEASE IX SCOTLAXD. [TACK.] 



LEAST At TIuN. PMNCTPLB OF. [Acnox, LEAST.] 



LEAST syfAKKS, METHOD OF. This is a method, which, 

 since it* first introduction, has been shown to be the method of finding 

 the most probable truth, when a number of discordant observations 

 have been made upon a phenomenon. The earliest attempt at any- 

 thing of the sort wo* made by Cote*, in a tract entitled ' Estimatio 

 Errorum in mixta matheai.' in which he very distinctly recommends a 

 proceM which i* identical with that of the method of least squares. 

 It is remarkable that Cotes proposes thU theorem not merely as a mode 

 of finding a convenient mean (a* was done by Legendre and Gauss), 

 but a* giving positively the most probable result. He even introduces 

 the hypothec!* of observations having different weights (though not 

 with perfect correctness), and comes a* near u possible to the assertion 

 afterwards proved by Lapkce. It will be worth while to quote the 

 passage, a* follow* : ' Mihi vix quidquam ulterius desiderari vide- 

 atur pustquam ostensum fuerit quft rationo Probabilitas maxima in his 

 rebus haberi poaut, ubi diverse observationes, in eundem finem 

 paullulum divers** ab invicem conclusions cxhibent. Id 

 i net ad modum sequentis exempli. Sit p locus object! alicujug 

 ax observations prima definitus, 9, r, t. ejuxdciu object! loca ex obser- 

 Tatiooibui aubsequenttbua ; rint insnper p, <j, R, 8, pondera reciproce 

 proportionalia apatii* evagationum, per quo) se diffundere possint 

 Error** ax observationibu* singuli* prodeuntes, quscque dantur ex 

 datia arrorum limitibus ; et ad puncta p, i/, r, t, intelligantur pondera 

 r, q. , *, et inveniatur eorum gravitatis centrum z : dico punctum 

 I fore locum objecti "'"* probabilem qui pro vero ejus loco tutis- 



!.. - 



Lagandre, in his work on comet* (1806), first distinctly proposed the 

 application of the method to any oase^and Gauss afterwards stated 

 that be had been in the habit of using it since 1795. Finally, Laplace, 

 ii> his Theory of Probabilities (1814), and we believe in a previous 

 paper published in the ' Memoirs of the Academy of Sciences, showed 

 that thi* method wa* in all esses the one which the principles of that 

 theory pointed out a* giving the result, whieh, from the observations, 

 has the greatest weight of probability in it* favour. The details and 



i of thin method may be found in the work of Laplace, 

 cited in the Berlin ' Astronomiscbn Jahrbuch. 1 fr 1834 and the two 

 [ year*, and in the treatise on Probabilities in the Encyclo- 



Th* meat simple eass of this method has been in use as long as 

 accurate obMrraUon* have been made, under the name of taking an 



can be thus obtained. If for example, we assume 

 anything but 6. say Ml. the assumed errors are then 21, 1-1 and 

 3.th* square* of which are 4-41, 1-21, and 8-41, the si 



is 14-03. more than 14. 



I. .-.-,' 



sum of which 



i of the method of least squa 

 thoM in which the result i* not simply observed, but is to be deter- 



'-'' 

 ith* 



upon the result* of observation. In all case* the 



rule i* the same: namely, that result ha* the greatest probability in 

 its favour, the aasumption of which makes the ram of the square* of 

 the errors the least possible, provided that all the observation* are 



equally worthy of confidence. Without entering into further explana- 

 tion, we shall give the results of one case. 



Suppose that A and a are to be determined by observation, the 

 required result being A-: a, or the solution <>f the equation <I.T=A. 

 Suppose also, which is essential to the simple form of the method 

 which we now give, that all the observations, both of A and , are 

 made under equally favourable circumstance*. Say that four observa- 

 tions are made of each ; those fur n being p, q, r, and : those for A 

 being r, Q, R, and s. If then all the observations were perfectly cor- 

 rect, each of the equations p x=r, q # = <), r x = n,t r s, would be 

 identical with a *= A. Supposing, however, that the observation* are 

 discordant, take what value of z we may, the several qiiantitir- 

 p, q x <j,r x B, xs, will not be (as they should be) each equal 

 to nothing. Whatever their value may be, the whole of each value 

 will be error : and the sum of the square* of the errors, or 



(px p) + (o;;r-<j) +(rz-R 



must be made the least possible. The value of x which satisfies thin 

 condition is 



j>* + j 1 + r* + * 



which is the most probable value. 



The method of least squares is now universally used in astronomy, 

 which ig-perhaps the only science in which so delicate a teat is abso- 

 lutely necessary. 



LEATHER MANUFACTURE. Leather (our, French; ledcr, Ger- 

 man ; leer, Dutch ; Ittder, Danish ; latter, Swedish ; cnoio, Italian ; 

 ciuro, Spanish ; ii/ijta, Russian.) i* prepared from the skins of animals, 

 or, it would perha|>s lie more correct to say, consists of that substance 

 after it has been chemically changed by the process of tanning. Thin 

 change is effected by means of a' substance residing in several vep 

 matters, to which the name of tannin has been given. When this 

 tannin, which is soluble in water, is applied to the hides of animals 

 from which the hair, epidermis, and any fleshy or fatty parts adhering 

 to them are removed, and which hides then consist wholly of gelatin, 

 also soluble in water, these two soluble substances so unite chemically 

 as to form the wholly insoluble substance called leather. The object 

 of the tanning process ig to produce such a chemical change in skins an 

 may render them unalterable by the external agents which tend to 

 decompose them in their natural state ; and in connection with the 

 subsequent operations of dressing, or currying, to bring them into a 

 state of pliability and impermeability to water which may adapt them 

 for the many useful purposes to which leather is applied. Effect* in 

 some degree similar are produced by forcing oil or grease into the pores 

 of the skin, or by preparation with alum. 



The preparation of skins by tanning or other analogous processes 

 hag been practised from the earliest times ; and, although it hag en- 

 gaged the attention of several scientific men, and has been the subject 

 of many curious experiments, it has received less modification from 

 recent improvements in chemical science than many other manu- 

 facturing processes. Several plans have been suggested with a view to 

 expedite the process, which, on the old system, is a very tedious one, 

 but having been found to deteriorate the quality of the leather, they 

 have been wholly or partially abandoned ; and others, which appear 

 to be more successful, are as yet adopted by a few manufacturers 

 only. 



Before noticing the tanning and currying processes, it will be de- 

 sirable to glance at the chief kinds of hides and skins converted into 

 leather. 



Among the hides of oxen, those supplied by bulk are thicker, 

 stronger, and coarser in the grain than those of cows ; while the hides 

 of bullocks are intermediate between those of the bull and the cow. 

 The thickest and most substantial leather now in general use is that 

 made from the hides of the half-wild cattle of South America. Such 

 leather ig employed for the sole* of boots and shoes ; for most parts of 

 harness and saddlery; for leather trunks, buckets, hose for fire- 

 engines, and pump-valves ; for the thick belts used in military accou- 

 trements; and for the gloves of cavalry. The thick biiff-ttather for- 

 merly used as armour, and which won pistol-proof, and would resist 

 the edge of a sword, was made from the hide of the urus or wild bull 

 of Poland, Hungary, and the middle and southern provinces of Russia ; 

 the animal itself being called bufe, whence the common II.-IIIK- of the 

 leather made from its hide. The skins of calra, though thinner than 

 those of cow*, are thicker than most other kinds of skin whirl 

 converted into leather. They are tawed or alumcd for the use of 

 bookbinder*, and are tinned and curriod for the upper leathern of boots 

 and shoes. It was formerly customary, in the south-west of 1 1 

 to slaughter cows when in calf; and the celebrated Limerick c 

 were made of the exceedingly fine and delicate skins of the in 

 calves. Slieep-tkint vary much in quality. A long fleece alw.. 

 dicatcs a thin skin ; much of the jelly l.iid up in that organ being, 

 perhaps, the material from which the fleece is elaborated. \Vli. u 

 limply tanned, sheepskins arc employed for inferior bookbinding, for 

 leathering bellows, and fir various otlier purposes for which a cheap 

 leather is required. All the vliit-lealhft; UK it ig termed, which is used 

 for wliip-lasne*, bags, aprons, ic., is of sheepHkin; as are also the 

 cheaper kinds of muti-lrrtt/icr, of which brushes, gloves, under- 



