Show ip en d ce 4 UNDERWOOD r OWN nt at it the co coast 51 Artil hey school it bt fort d monroe Vs va une uncle e sam la is turning out the latest pattern patter of mod ern heavy artillery tile A it I 1 guard cast artillery title y officers and such the of if the regular eta establish bliSh mant at Us KB bar have not at yet be beet through this school have been ordered down in two mo sections the first of which already tug bern been graduated upon the const coast artillery corps has been bi so thrust tile the burden of handling the heavy bell ordna jica with which the arav Is nanct ahlin ills in t the he geld field w will be manipulated by meth ads aa datore or I 1 leeg alig resembling bl ig the meth forth ad oda already laid aid down daoa for a sea coast at ordnance these methods are tar far different from those h am used by the field artillery p proper ml that 11 ia the light three ih inch reiles and ad 4 7 inch h 11 11 th the present day heavy artillery boffl in ran must I 1 be a mathematical mahln matteal shark a railroad engineer and tin an cort in handling citing gasoline motors besides having an intimate indman knowledge of gun FOR nery davs sen ser writer write r in 1 the new york herald wf equipment I 1 has ahrmed from the battery comman clor a ruler of the field artilleryman to a slide rule elle a transit and a book of logarithms in addition lie must cat ca t understand per factly the manipulation of if heavy arte masses c tc termed ed the art of mechanical fur for his ha guns will ill tend not be a seen rely empl em placed ced in concrete acre but will be exia exposed d to the mercies of the open road with co consequent overturn ing and sudden madl shillings shit ting he most linow know how to use tackle of nil all sorts suit and I 1 ID general know all the tricks of if the modern contractor ahe officers officer who bo came down to fort monroe verc err nearly dearly all graduate of he no national I 1 ional I 1 guard courses proscribed prescribed by the war and ad were wo folly competent pet at to hindle bindle seacoast sea ast ordnance in it the forts forb to which chev were US as signed da tied they thought that their knowledge it was amid and it would uld have I 1 been for this work perhaps but after a dy day 0 or BO they found out that adle t M k knowledge iso edge awaa a essential entin to the them as basic it was only the tha beginning gunnery tile big thing the alg thing of course was run iran nt ry this included a practical knowl bawl 1 edge dge 1 of ballistics the science of the 1 14 of sophes ads then through ugh the air ballistics ballistic Is a very exact esset science and in the these daa of precision 1 la I 1 ly essential for far the artil artilleryman lorm it re ete dmd t tf language tor far the layman it consists sl in the know ledge 0 of just jt J t how far a given elven piece of ordnance will hurt hurl its projectile under all conditions condition vry very simple imph ay Y you yes yea under r stan andied t conditions every gun when ubbo it t Is turned tu r ned out art train from tile maker Is a lumis known t to 0 lies a certain projectile to 0 ordet rt aln range rage at ti a certain elevation T thew bedo data is arc ro compiled in tables and are theoretically tile the same ame it for all 11 runs a ilithe I 1 of tha IS same mine caliber and model three these table mr are known a as range go tables and the road conditions t as given give for far the II it bring of ali ar for these theoretical ranges bre koozo a as range table conditions Xe lt member bi BIN now some of the principal range table condition or assumptions are that th t tile the earth 1 Is flat and ad due coee not at re volve j that tile the atmospheric condl amz rt ami aona are d that there the Is 1 no wind i that filst the gun and target arc am on the th nune in leu P and ad that the action of if grail tyla contant constent throughout the trajectory all veil uell and good we IV know aw that hot our gun then will lies fire it its projectile it it as sav 1 10 yards under range to table 11 I in other word ards given the he aboe conditions condition it will it prop pi let alv laid in three direction tion hit a target dow yards yard away lot but unfortunately ty for or US ns the earth in I 1 Is not at flat t I 1 our tar get la is 10 yards away lly and ad feet so abe the level of the gun gow there them la Is a ten tel aill mile wind awl moving blowing straight cross across the line gun bourg target t the thermometer at Is u ap P to 85 and the barometer has dropped to 29 will the projectile hit the target now 1 not unless you cor the elevation of the gun tor far some of if th these conditions audit an nod it its laying top for the others how are you yon going to do it first you must find the time force with which you your projectile cleaves cleavia the air this Is called the ballistic baHt lc coefficient sell and Is ig reduced by a simple farm formula to tn a figure knowing the weight of the 1 I jaborn Jt Born and its diameter III meter ehod the bat ballistic a tj ro our is ia ir easily ml gal th at air aa is C check I 1 YOU ton have now taken the the first step yo yon u have the force of projectile to P penetrate the atmosphere under stands ard emdell em conditions dill but this force farm varies rim with the 0 on a heavy muggy day the atmosphere 1 la denie deal and you lim will be d the check ing effect it will havo on nour lour projectile tit plot pv means of elaborate tables one can find just jolt what this effect la Is rod we I 1 apply it to the original formula also in the atmospheric factor J la to ID eluded the temperature for in hot bat weather our powder charge when IK 19 exerts more strength in becom into rules gawa than it does on a cold d day I 1 y so to far so BO good what about this troublesome wind nind that 1 Is blowing if it blows against the project projectile Is it along checks it it if with ltv it it helps help it along so go we have two varying facca actors wl ich the juggles bv nv unit ing inc trigonometry until he gets them in to terms its whore where he can in once more are change hla his ballistic efficient coefficient co making it larger or smaller as ag the wind vind sm police or accelerates the projectile not quite bo easy US is you thought Is it if but we a are not of through jet wo we know that under mme ame table cordi conditions our propelling charge has a fw force that ches the pmj projectile til an initial velo velocity cit of so in many any in font at sec ec amp say my 20 2 0 but our powder has been stored stated in a dugout whose tern ton per aperture ture la Is not normal so by more fig a tiring we find out just what this real mat velocity for the dav la is now we wa ran can begin to figure what chat elevation the go gun mut haw have to trawl travel that 10 W sed ard path put h to the target ev bv di dividing filber our old friend 0 a aa the bI ballistic listle coefficient co efficient la Is termed by bv the ile al distance 11 towee in feet that tit the projectile must travel we get a reference nuro nom her loar this number w tati take with alth Us ua numb DiP and ad bit bin v our no nowa n in mora 0 tables ua on tit til wa As find opposite this alil number in a colun column headed by the muzzle vol velocity ltv another other number lumber this number multi piled by bv C again get gives give wa Is the sine of 0 i to twice I 1 ca the angle of d departure op arture A quick g glance 1 I lot into a table of at immroth mic ade gi gives this ihl to US ns and dividing by two we have a 4 cigua algue in and minutes that lepri represents ts the angle ellich v alch the go gun must be it elevated 1 voted from the borl horizontal itaf to send bend its projectile yards tod walt wait a minute our target ts Is flat feet aboe b the level 1 vel of the iran gun ano alo bec becse because se of the curvature a t ore of tho the earth this feet helehe li has a s been reduced lomeo someo somewhat hat so once more w we delwinn del delve wint into mathematics to cor or met th aba curvature of the earth and height of site its of if tile the target the result we subtract train from the angle found a and nd this time our gun it Is ready for h business u sines la Is it no MG it t ts Is not so io easy th the influenza of 1 11 the rifling F esery cry rifled died piece ot of ordnance ord do nanca 1 ini paita a twist a 1 to ita projectile and t athla his twist m caauwa u the to deviate at from its comilia in our service ethis this deviation called drift 1 la to the tha right and la Is to n ratio with alth the ariee 19 it ft la 1 constant therefore tor for mch each range nod nad we oe find it very mall either fir bv multi math em u computation a or it houi drift 1 ta bl blab also we go back to our or wind problem and find and slot effect the wind will have 1 la pushing the from its course either to the right or left these tso tw 0 corrections athe ahe lire brought together and determine m amount in degrees and minutes t that the muzzle mi ot of the gua can must be shift ed from the target to the right or left in order that the tha pride projectile ittle will curve toward it its goal at last we have our one sun gun controlled so BO that it will hit the turg target t tarry just a moment L A gun the text books tell us li Is the simplest form ot of gas gaa engine did you ewe ever know tiro gas engines of the same model that acted alike neither will t two guns uns of the nine model made the fifty per pep cent zit foiw you here hava a an automobile you knew that the piston rings wear me ant on allow ing van gases to escape and thus thua reducing th the force fares with which the paston la in f forced md do down also the ty cylinder lindor be sit comes scored with the same moult now how if you im Y your go gun in many any it times the s same thing happens tile the broj tile 1 la uie the piston and the retaining bond band of copper I 1 the pi piston s to ring that seals the bore if the bore la Is eroded or if the r rotating orating bands are an not per feet fact a certain escape of gam occurs or and the flight of the projectile Is con sequent y affected cled thIle again there way may be a difference diff dif fmc frence in 14 the weight weigh of powder it or charters charges or in the weight eight of the projectiles which will she give slight variations in the flight ot of the projectiles so that the battery commander must know the it diversion persian of each piece this he finds out from observation of his shota and it changes US as tile the fun com a browa older by figuring biguri the deviation of a certain group of of projectiles from the target and which are known as trial shots share or it fire for adjustment he be finds out what hat Is known as the mean san error of the gun this multiplied by the factor to actor well known icon to stud students is of abilities bili tips gives the mein probable er ec ro multiplying by two the I 1 in bards ads 1 is what I 1 Is known Us as tile the SO 50 per par cent zone tone within which 50 per mat cent of his projectiles will nill fall this tation to Is done longitudinally and lot i dinally to giving a cert certain I 1 oblong I 1 9 strip if tile the center canter of this ol 01 trip strip me can be placed on the target bv observation of fire the battery commander has hag done all that he can and mey now nin open fire tor far effect four timi the 50 per par c cent tit tone rone gives the per cent zone one within which practically all his show shots 1111 fall Know knowledge ledee of these call zones Is nil ill lon partial iv ev this means he ba een can figure out oat hob ban a neat lie be can come came 1 to I 1 our or own 1 past mt line tr trenches without murdering our infantry and what la Is almost as 1 important when it Is nere necessary sory to save ammunition le he can easily compute how many shots bots mil be necessary to make a certain number of if hins alta a on a given give target and what shat about inic e the enemy airplanes mrs art on the alert and all 11 jiin in positions must t be the battery cono commander dietr al must at be a matter master of AI able to met erect shIl shelters and on under a I 1 thair lr or to build his em placement placements while ahil hy by tile the exer it die of dl discipline lie he wt restrains raf his men fro from making tracks track about the post III alons which W will ill give away army to I 1 the h all seeing ever of at the centers camera in ft the air tile the fact that guns gun are am mobil mounted ded there so that Is why hy flie dent officers at rott fort monroe blistered their hands and strained t 1 t their r hartfi ol 01 9 e erect e to lug camouflages noting D and digging dugouts and ad baraf bp raf I 1 that it la IS w hy by they dove davs i anil ad er crawled Is oil under er motor trucks suit and do delved ire into I 1 and gear ease emer emerging US ulrey ml and grimy but bat hop happy I 1 thit it la why they tolled for far s st I 1 out lengthy b hours at working 1 aroble problems ain in trifono trigonometry a y until angles algiea it danced I 1 t before if m their air edles eaf as when they tried to ill 11 and a endle a chains of go that courtl tile themselves solves through their lr to bi DIW bin coll cells i |