LAC 



498 



LAG 



Lactometer. o f the weight upon the top, and that of the division to- 

 "*"" "Y"**' gether, and opposite the same, formed upon the side, 

 will be shewn the strength of the milk. 



Examples of New MM. If, in the temperature of 

 72, the lactometer with the weight 40 sinks to nine 

 upon the stem, fix the slide so that the star shall be fa- 

 cing 72; then opposite 49 will be found 100, the 

 strength of the milk. Again, if in 60 the lactometer 

 with 50 on the top sinks to 6 upon the stem, the slide 

 being fixed for new-milk, so that the star shall be at 

 60 degrees of heat, then facing 56 will be found 110, 

 the strength of this milk in proportion towards the 

 other, provided it is equally replete with cream. To 

 discover which, it becomes requisite these two samples 

 should stand a certain time, that the cream may rise, 

 which, being taken off, they are to be tried with the 

 lactometer again : and as- the cream is evidently the 

 lighter part, the milk will appear by the lactometer 

 denser or better in quality than before. Suppose the 

 milk in the first example to be 57 by the lactometer in 

 60 of heat, then the strength by the skimmed-milk 

 side of the rule will be 112. And admit the second 

 example of new-milk to be 58 in 64 when skimmed, 

 the strength would be 116. 



As a comparison, say 



No. 1. 



No. 8. 



Nenf-milk 

 Ditto skimmed 



100 

 112 



Difference 12 



New-milk 

 When skimmed 



110 

 116 



Difference 



From which it appears, that No. 1. haa produced a 

 larger quantity of cream than No. 2, and consequently 

 may be deemed the better milk. Some instances have 

 occurred where the strength of new-milk has only been 

 about 80, and when skimmed near 100. Thus it may, 

 without the least impropriety, be called a milk much 

 better adapted for making butter than cheese ; the se- 

 rum or whey in general being near the same density. 



The instances in which the lactometer may be use- 

 ful, are, according to the same writer, in discovering 

 what breeds of cattle are most advantageous ; \r hat food 

 in the winter season, whether carrots, turnips, potatoes, 

 &c. are best ; what the effects of different pastures may 

 be ; how far particular farms are best adapted to mak- 

 ing butter and cheese ; how far the inconvenience of 

 large cheeses in some dairies being too rich to stand 

 may be prevented, by discovering when this redun- 

 dancy of richness exists in the milk ; and in fixing a 

 standard for the sale of this useful article of life. 



A standard for skimmed milk may readily be fixed, 

 by saying what strength the common saleable skimmed 

 milk shall be by the lactometer, or what its specific 

 gravity shall be in relation to that of water in the tem- 

 perate degree of heat, and that an easy comparison may 

 be made between the specific gravity of any milk, and 

 its lactometer strength ; this instrument is so construct- 

 ed, that one of specific gravity shall exactly correspond 

 with three of strength ; that is, the strength of 90 by 

 the lactometer is a milk whose specific gravity is 1030, 

 to common pump water 1000. From a number of ex- 

 periments and observations, it is observed, that the 

 common saleable skimmed milk in Liverpool is from 

 52 to 64 of strength, that of new milk from 70 to 80 ; 

 but it would be difficult to fix any standard for the lat- 



Ladrone. 



ter, unless some mode could be devised to discover Ladanuro, 

 whether it was mixed with old milk or not. The only 

 method would be, after fixing the strength of it, to try, 

 by letting it stand, to discover if it product that quan- 

 tity of cream, which as new milk it might reasonably 

 be expected to do. 



Another lactometer, upon a different principle, has Lactometer 

 been recently constructed at the desire of Sir Joseph with glass 

 Banks, by Mr. Thomas Jones, mathematical instrument lubes - 

 maker, Charing Cross. Sir Joseph has described it in 

 the Farmer's Journal, and it promises to answer the in- 

 tended purpose. 



It consists of any number of glass tubes, of the same 

 internal diameter, which is generally about one-third of 

 an inch, and about 1 1 inches long. They are closed at 

 one end, and open and a little flanched at the other, 

 like the test tubes used by chemists, and are mounted 

 on stands in the same manner. At the distance of 10 

 inches from the bottom of each tube is a mark, with 0, 

 or zero, placed opposite it ; and from this point the , 



tube is graduated into tenths of an inch, and numbered 

 downwards for three inches, so that each division is 

 T4 5 th of the tube. If several of the tubes are filled with 

 new milk at the same time, and placed at the same tem- 

 perature, the cake of cream will form at the top, and 

 its thickness or quantity will be indicated by the divi-' 

 sions. In this way experiments may be made on the 

 relative quantities of cream produced by different sys- 

 tems of feeding, or by different animals fed and placed 

 under different circumstances. The per centage of 

 cream is thus obtained by simple inspection. See 

 Brande's Journal, vol. iii. p. 393, 394. 

 LADANUM. See LABDANUM. 

 LADOGA, or LADOZKOI, is a large lake of Russia, 

 in the government of Viborg, lying between the Gulf 

 of Finland and the Lake of Onega. It is about 175 

 versts long, and 105 broad, and is deemed one of the 

 largest lakes in Europe. The shores of the lake have 

 a flat coast, and a sandy beach. It produces a great 

 number of seals. On account of the numerous shifting 

 sand banks, and the dreadful storms which prevailed, 

 Peter the Great, in 1718, projected the famous Ladoga 

 canal, cut along the southern shore, from the Volkhof 

 to the Neva. It was finished during the reign of the 

 Empress Anne, and was at first carried only as far as 

 the Kabona, a rivulet which enters the lake to the east 

 of Schlusselburgh ; but it now stretches without inter- 

 ruption from the Volkhof to the Neva. It is 67| miles 

 long, 70 feet broad, and the mean depth of water is 7 

 feet in summer, and 10 in spring. It is supplied by 

 the Volkhof and 8 rivulets, and has 25 sluices. The 

 barks enter through the sluices of the Volkhof, and go 

 out through those of Schlusselburgh. In 1778, 4927 

 vessels passed through this canal. The lake of Ladoga 

 is connected with the Baltic by the Neva, with Lake 

 Onega by the river Svir, and with Lake Ilmen by the 

 Volkhof. See NAVIGATION INLAND ; Tooke's Rttsfian 

 Empire, vol. i. ; and Coxe's Travels in Russia, TO!, iii. 

 p. 374, where the reader will find a plan of the Ladoga 

 canal. 



LADRONES, or MARIAN ISLANDS, a large archipe- situation 

 lago on the verge of the Pacific ocean, stretching from and disco- 

 north to south about 200 miles, are situated between the very. 

 ] 1 and 21 of North Lat. and nearly under the 145th 

 parallel of East Long. They were originally discovered 

 by Magellan in 1521, who first gave them the name of 

 Las islas de las Velas, from the peculiar sails of their 

 prows; but afterwards denominated them Las islas de los 

 Ladrones, from the thievish disposition and dexterity of 



