COLLECTIONS IN ECONOMIC OEOLOGY AND METALLUH(;Y. 205 



A series of pnniice stones ;iii.l ivlatr.l phkIim-Is froin thr works of 



Messrs. R. J. Wa<l«Ull ^ ''«»•, >'^^w York, shows: 



(1) Pumice stono. lump. (.Ml.M. > 



(-2) rnuiicttstono.nour.groun.l ami holt.-.l. (r>4ir.4.) 



(3) PmuicoHtono.No. 1. jjrouml an.llx.ll.Ml. (Ml.'.r,.) 



(4) Pumice 8t(mo. N...U.Krouml aii.l I.oU.mI. (r>4ir)6.) 



(5) Kotton Htoms lump. (fvU.'.O.) 



(6) Rotten Htono, unuiml and b()lt4><l. (.Ml.'.:<. ) 



(7) Putty powtlcr, lifHt ([uality. (541 Jl».) 



(8) Scotch hone, rou<;h. (r>414r..) 



(9) Scotch hone, trimmed. (.'>4147.) 

 (10) Scotch hone, slip. (r)414H. ) 



Two specimens of garnet are shown : 



(1) Kouf,'h crystal, iiurko County, North Carolina. (56322.) 



(2) Crushed. H.irk.' County, North Carolina. (6<)583.) 



MANUFACTT RE OF SANDPAPER. 



The collection illn.stratinti the process of tnamifacturinc: sandpaper 

 was presented bv Messrs. Baeder, A<lanKSon .S: Co., Philadelphia, Penn- 

 sylvania and shows all the materials for making the paper, a full .series 

 of the lump and -ronnd abradinji" materials, au«l a series of the sand and 

 emery paper produced. 



(1) Manilla rope, used for maniifacturiii;; the paper. (55239.) 



(2) Paper pulp, n..-u.illa rope beaten int.. pulp, ready to he made ,nT.. paper 



(5^''2-l^'-) ,. /r-.M1 > 



(3) Manilla paper, made fn.u. rope, ready for the dint ..r emery. (.,;>241. ) 



(4) Olue stock, pieces of hi.le tnun which glue is made. (55237.) 



(5) Glue, made from hide; used lor fastening the dint and en.ery to the paper. 



(^-^•^ rii„l rock or -iiiurtz. 



(1) To he ;,'rouud and ;:lued on In the pai..r: from Maine. (;V,243.) 



(2) From Pennsylvania. (.'•.">244.) 

 Ground, ready to h.- ^lued on to the paper: 



(3)Si.cOO. (55253.) 1 (7) Size If (55257.) 



4 Size 0. (552.54.) (H) Size 2. (:.;.2.,s.) 



5 Size i. 55255.) I («) !*- !*' 1^^ V 

 ;.;U;izel. (55256.) (10) Size 3. (:>.2hO.) 



An averape .sample of these sizes, analyzed in the lahratory ..f ,he nep..r.menl. 



l.y Mr. .1. A. Allen, jjave— 



ri<r ri'iit. 



Silica (SiO;) ''•'• ;||' 



Alumina (Al.Oa) .-.-. '1^'*'^ 



Se8t|uioxideof iron (,l'V;Oi) ' ^ 



Linio (CaO) ^^* ^J^ 



Magnesia (MnO) 



,1) Flint paper, a roll as made and rea.ly to be cut into sheets : the .lint or quartz 

 ha« been fastened on to the manilla paper by the kIuc. (.m2<.2.) 



(2) Flint paper, a series of ei^-ht sheets, showing the ditferent sizes of ground Hint 

 used. The sheets are ..ne-fourtb the regular size. (552t">4. ) 



