338 



stance, consisting of four coals of paper, 

 j)astcd one on the other, and so on, ac- 

 cording to the diameters of the tubes, 

 increasing in number of coats as the size 

 may be augmented, applying last of all 

 the coat of vellum. The above-men- 

 tioned number of four coals of paper is 

 found to succeed for tubes to tiie extent 

 of two inches in diameter, beyond which 

 a coat or coats of post or writing paper 

 may be added, as shall be found recjui- 

 sitc. The snbstance so composed is 

 formed into tubes, by being pasted ou 

 moulds or treblets made of brass or com- 

 pound metal, which arc adapted to the 

 implement called a draw bench, liilherto 

 used for drawing brass or metal only, 

 and drawing tiic same tlirough brass 

 boles made for that purpose. The tubes 

 are tempered to a ceitain hardness by 

 drawing them through one, two, or more 

 Violcs, which is aljsolntely necessary lo 

 make the tubes cylindrical round, and of 

 a true form. It also renders them, by 

 the eorreotness of their shape, fit to re- 

 *eive brass or metal rims, rings, and 

 screws. 



The side of the first coat of paper, 

 which is called the water coat, nz. that 

 which is intended to form tiie inside sur- 

 faces of iIk; lubes, is stainetl black pp- 

 V ions to its being put on the treblet. y\ ny 

 black stain may b« used, but Mr. Adams 

 prefers the following preparation, viz. lu- 

 dian ink witii conunon writing ink, in tlie 

 proportion of a (piarter of an ounce of 

 the former to a gill of the latter, lo which 

 may be added abouthalf a quarter of an 

 ounce of gum, well dissoKcd in about 

 half a gill of water. This jireparation is 

 Jakl on the said first coat of paper with a 

 brush; and the said first coat of paf»or, 

 while wet with it, is placed on the tre- 

 blet, which is previously [jrcased with 

 .suet, or other grease, 



TI)C first coat of paper, or water eoat 

 may, however, be moistened with water 

 nnly, previous to its being placed on tiie 

 Ireblet ; and in that case the inside sur- 

 face of trie tube may be afterwards 

 stained black «ith tlie said prepaiatioii, 

 by means of a brush dipped in it being 

 drawn through the tube. 

 • The next, or seeond coiit of post or 

 writing paper, is to he well moistened 

 witl) past« on both siiles, and then laid 

 «u the water coat, 'i'his slioiild be 

 aiJK'Oinplishcd while the latter is }<! 

 moist. 



'J'he brown or bincjxaper is laid on the 

 second eoat after the sami' manner, and 

 there the worL ce'ascs liil the coals so 

 f>asted together are dry and bard cuoit;;h 



Patents lately Enrolled. 



fNoy. 1, 



to admit of its surface being levelled, 

 which is eflected by filing. This pro- 

 cess is necessary, in order to correct th« 

 inequalities, and ronovc the gritty sub- 

 stances which are generally to be found 

 in paper, but especially in the brown or 

 blue sorts. AVIien the last-mentioned 

 sJirface is made smooth, the next coat 

 of post paper should l)e pasted thereon, 

 and last of all the vellum. Care should 

 be taken to incorporate tho paste well 

 with the paper; and iu the stiffer sorts oC 

 paper it would be proper to moisten 

 them in water, first of all squeezing th« 

 same out liy pressure previous to the ap- 

 plication of the paste: this precaution 

 should be observed with the outside or 

 vellum coat also. The paste is made in 

 the usual manner, with the exception, 

 tiiat a small portion of powdered resin 

 (about a «]uarter of an ounce to a pint) 

 should be put into it, in order to stit^ 

 fen it. 



The treblets are for the most part 

 mailc hollow; in tiie larger sizes they ar« 

 cored tiirongh in the casting; in the 

 smaller ditto they are drilled or bored ; 

 and iu the smallost of all they are left 

 solid. The reason for their being made 

 hollow is in one respect to reduce th« 

 quantity of brass or motal, thereby to 

 save expence. In another point of view, 

 to enable the work»nan lo place therein 

 an iron heater, made red hot, by the aid 

 of which artificial heat the moisture con- 

 tained in the difl'erent coats is dried with 

 tolerable quickness, the same is thereby 

 sooner piepared for the draw-bench, and 

 the whole of the subsequent mechanical 

 process expedited. 



'J'he cell containing the object glass or 

 glasses. Mr. Adams forms ot ivory or 

 wood lor lightness : he omits the cover 

 nsnally placed at tliat end for the sam» 

 reason. 'I'he same in some instances is 

 lined with a thin Urassring, and the coun- 

 ter screw, which encloses and secures 

 the glasses, he usually makes of brass. 

 The head of the instrument is made also 

 of ivory or wood for lightness; box wood 

 is generally preii»rred. He has given 1» 

 this part of the telescope a new form, 

 which he occasionally paints, gilds, var- 

 nishes, and otherwise ornaments. H» 

 has also discontinued Ihe use of th» 

 sliding shutter at the head of the tele- 

 scope, as it was constantly being out oi 

 repair, and from its being retained gave 

 to the head a clumsy appearance. 



The second part of his invention cori- 



sisls of the introduction of an additional 



glass in a new manner into telescopes of 



small sixe, uMially called prosject glasses, 



2 whereby 



